Download Final Exam Review

Final Exam Review
Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Determine whether the given value is from a discrete or continuous data set.
1) The temperature of a cup of coffee is 67.3°F.
A) Discrete
B) Continuous
1)
2) The total number of phone calls a sales representative makes in a month is 425.
A) Continuous
B) Discrete
2)
Determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate.
3) The temperatures of eight different plastic spheres.
3)
A) Nominal
B) Interval
C) Ratio
D) Ordinal
4) Salaries of college professors.
A) Ratio
B) Nominal
4)
C) Ordinal
D) Interval
Perform the requested conversions. Round decimals to the nearest thousandth and percents to the nearest tenth of a
percent, if necessary.
7
5) Convert the fraction
to an equivalent decimal and percentage.
5)
11
A) 0.636, 6.36%
B) 0.756, 756%
C) 0.636, 63.6%
D) 0.756, 75.6%
Solve the problem.
6) On a test, 55% of the questions are answered correctly. If 44 questions are correct, how many
questions are on the test?
A) 11
B) 125
C) 55
D) 80
Identify which of these types of sampling is used: random, stratified, systematic, cluster, convenience.
7) 49, 34, and 48 students are selected from the Sophomore, Junior, and Senior classes with 496, 348,
and 481 students respectively.
A) Cluster
B) Systematic
C) Random
D) Convenience
E) Stratified
8) A sample consists of every 49th student from a group of 496 students.
A) Convenience
B) Cluster
C) Systematic
D) Random
E) Stratified
1
6)
7)
8)
9) A pollster uses a computer to generate 500 random numbers, then interviews the voters
corresponding to those numbers.
A) Cluster
B) Stratified
C) Convenience
D) Systematic
E) Random
9)
10) To avoid working late, a quality control analyst simply inspects the first 100 items produced in a
day.
A) Random
B) Convenience
C) Cluster
D) Stratified
E) Systematic
10)
11) The name of each contestant is written on a separate card, the cards are placed in a bag, and
three names are picked from the bag.
A) Convenience
B) Random
C) Stratified
D) Cluster
E) Systematic
11)
Provide an appropriate response.
12) The following frequency distribution analyzes the scores on a math test. Find the class
boundaries of scores interval 40-59.
Scores
40-59
60-75
76-82
83-94
95-99
A) 39.5, 59.5
Number of students
2
4
6
15
5
B) 40.5, 59.5
C) 40.5, 58.5
D) 39.5, 58.5
13) The following frequency distribution analyzes the scores on a math test. Find the class midpoint
of scores interval 40-59.
Scores
40-59
60-75
76-82
83-94
95-99
A) 49.5
12)
Number of students
2
4
6
15
5
B) 49.0
C) 48.5
2
D) 50.5
13)
14) The frequency distribution below summarizes the home sale prices in the city of Summerhill for
the month of June. Determine the width of each class.
14)
(Sale price in thousand $) Frequency
80.0 - 110.9
2
111.0 - 141.9
5
142.0 - 172.9
7
173.0 - 203.9
10
204.0 - 234.9
3
235.0 - 265.9
1
A) 28
B) 61
C) 31
D) 30
Construct the cumulative frequency distribution that corresponds to the given frequency distribution.
15)
Number
Speed of cars
0-29
4
30-59
16
60-89
60
90-119
20
A)
B)
Speed
Less than 30
Less than 60
Less than 90
Less than120
Cumulative
Frequency
100
80
82
4
Speed
Less than 30
Less than 60
Less than 90
Less than120
Cumulative
Frequency
0.04
0.20
0.80
1.00
Speed
0-29
30-59
60-89
90-119
C)
Cumulative
Frequency
4
20
80
100
D)
Speed
Less than 30
Less than 60
Less than 90
Less than120
3
Cumulative
Frequency
4
20
80
100
15)
Provide an appropriate response.
16) The frequency distribution for the weekly incomes of students with part-time jobs is given
below.
Construct the corresponding relative frequency distribution. Round relative frequencies to the
nearest hundredth of a percent if necessary.
Income ($) Frequency
200-300
60
301-400
73
401-500
91
501-600
89
More than 600
15
A)
Relative
Income ($) Frequency
200-300
18.29%
301-400
22.26%
401-500
27.74%
501-600
27.13%
More than 600
4.57%
C)
Relative
Income ($) Frequency
200-300
27.33%
301-400
27.38%
401-500
4.60%
501-600
18.07%
More than 600
27.41%
16)
B)
Income ($)
201-300
301-400
401-500
501-600
More than600
Relative
Frequency
15.5%
22.1%
31.3%
16.2%
14.9%
Income ($)
200-300
301-400
401-500
501-600
More than 600
Relative
Frequency
12.5%
20.1%
37.3%
15.2%
14.9%
D)
Find the mean for the given sample data. Unless indicated otherwise, round your answer to one more decimal place
than is present in the original data values.
17) Andrew asked seven of his friends how many cousins they had. The results are listed below.
17)
Find the mean number of cousins.
18 12 7 13 7 2 7
A) 8.9 cousins
B) 9.4 cousins
C) 10.9 cousins
D) 11 cousins
Find the median for the given sample data.
18) The ages (in years) of the eight passengers on a bus are listed below.
10 7 26 16 21 43 40 30
Find the median age.
A) 23.5 yr
B) 24.5 yr
C) 26 yr
D) 21 yr
Find the mode(s) for the given sample data.
19) 92 56 32 56 29 92
A) 92
B) 59.5
D) 92, 56
18)
19)
C) 56
4
Find the midrange for the given sample data.
20) A meteorologist records the number of clear days in a given year in each of 21 different U.S.
cities. The results are shown below. Find the midrange.
72 143 52 84 100 98 101
120 99 121 86 60 59 71
125 130 104 74 83 55 169
A) 98 days
B) 110.5 days
C) 117 days
D) 112 days
Find the mean of the data summarized in the given frequency distribution.
21) The test scores of 40 students are summarized in the frequency distribution below. Find the
mean score.
Score Students
50-59
13
60-69
6
70-79
7
80-89
7
90-99
7
A) 71.8
B) 68.2
C) 74.5
20)
21)
D) 64.6
Solve the problem.
22) Elaine gets quiz grades of 71, 75, and 64. She gets a 60 on her final exam. Find the weighted mean
if the quizzes each count for 20% and the final exam counts for 40% of the final grade. Round to
one decimal place.
A) 67.5
B) 65.0
C) 68.2
D) 66.0
Find the range for the given sample data.
23) Rich Borne teaches Chemistry 101. Last week he gave his students a quiz. Their scores are listed
below.
30 31 47 29 32 11 48 41 50 59 37 22
A) 11
B) 2
C) 48
D) 59
22)
23)
Find the variance for the given data. Round your answer to one more decimal place than the original data.
24) 6.6 8.5 4.6 1.7 2.4
24)
A) 6.46
B) 8.08
C) 12.80
D) 7.98
Find the standard deviation for the given sample data. Round your answer to one more decimal place than is present
in the original data.
25) 114 105 245 193 295 248 229 229 170
25)
A) 59.9
B) 63.6
C) 25.4
D) 67.9
5
Find the coefficient of variation for each of the two sets of data, then compare the variation. Round results to one
decimal place.
26) Listed below are the systolic blood pressures (in mm Hg) for a sample of men aged 20-29 and
26)
for a sample of men aged 60-69.
Men aged 20-29: 116 125 132 118 131 123
Men aged 60-69: 128 151 140 125 164 139
A) Men aged 20-29: 8.7%
Men aged 60-69: 4.7%
There is more variation in blood pressures of the men aged 20-29.
B) Men aged 20-29: 5.3%
Men aged 60-69: 10.3 %
There is substantially more variation in blood pressures of the men aged 60-69.
C) Men aged 20-29: 5.0%
Men aged 60-69: 8.4%
There is substantially more variation in blood pressures of the men aged 60-69.
D) Men aged 20-29: 5.5%
Men aged 60-69: 10.7%
There is substantially more variation in blood pressures of the men aged 60-69.
Find the range, variance, and standard deviation for each of the two samples, then compare the two sets of results.
27) When investigating times required for drive-through service, the following results (in seconds)
27)
were obtained.
Restaurant A 120 67 89 97 124 68 72 96
Restaurant B 115 126 49 56 98 76 78 95
A) Restaurant A: 57 sec; 493.98 sec2; 22.23 sec
Restaurant B: 56 sec; 727.98 sec2; 32.89 sec
There is more variation in the times for restaurant B.
B) Restaurant A: 75 sec; 493.98 sec2; 22.23 sec
Restaurant B: 70 sec; 727.98 sec2; 26.98 sec
There is more variation in the times for restaurant B.
C) Restaurant A: 57 sec; 793.98 sec2; 28.18 sec
Restaurant B: 77 sec; 727.98 sec2; 26.98 sec
There is more variation in the times for restaurant A.
D) Restaurant A: 57 sec; 493.98 sec2; 22.23 sec
Restaurant B: 77 sec; 727.98 sec2; 26.98 sec
There is more variation in the times for restaurant B.
Find the standard deviation of the data summarized in the given frequency distribution.
28) The test scores of 40 students are summarized in the frequency distribution below. Find the
standard deviation.
Score Students
50-59
5
60-69
13
70-79
5
80-89
8
90-99
9
A) 13.3
B) 12.6
C) 14.7
D) 14
6
28)
Use the empirical rule to solve the problem.
29) At one college, GPA's are normally distributed with a mean of 2.9 and a standard deviation of
0.6. What percentage of students at the college have a GPA between 2.3 and 3.5?
A) 95%
B) 84.13%
C) 68%
D) 99.7%
Use the range rule of thumb to estimate the standard deviation. Round results to the nearest tenth.
30) The heights in feet of people who work in an office are as follows.
5.8 6.1 5.9 5.4 5.6 5.8 5.9 6.2 6.1 5.8
A) 1.2
B) 0.1
C) 0.2
D) 0.5
Solve the problem. Round results to the nearest hundredth.
31) The mean of a set of data is 5.73 and its standard deviation is 3.44. Find the z score for a value of
13.87.
A) 2.37
B) 2.13
C) 2.61
D) 2.67
Find the number of standard deviations from the mean. Round your answer to two decimal places.
32) The annual snowfall in a town has a mean of 38 inches and a standard deviation of 10 inches.
Last year there were 63 inches of snow. How many standard deviations from the mean is that?
A) 0.44 standard deviations above the mean
B) 2.50 standard deviations above the mean
C) 0.44 standard deviations below the mean
D) 2.50 standard deviations below the mean
29)
30)
31)
32)
Find the z-score corresponding to the given value and use the z-score to determine whether the value is unusual.
Consider a score to be unusual if its z-score is less than -2.00 or greater than 2.00. Round the z-score to the nearest
tenth if necessary.
33) A body temperature of 99.5° F given that human body temperatures have a mean of 98.20° F
33)
and a standard deviation of 0.62°.
A) -2.1; unusual
B) 2.1; unusual
C) 1.3; not usual
D) 2.1; not unusual
Find the percentile for the data value.
34) Data set: 4 6 14 10 4 10 18 18 22 6 6 18 12 2 18;
data value: 14
A) 70
B) 52
C) 35
7
34)
D) 60
Construct a boxplot for the given data. Include values of the 5-number summary in all boxplots.
35) The weights (in pounds) of 30 newborn babies are listed below. Construct a boxplot for the data
set.
5.5 5.7 5.8 5.9 6.1 6.1 6.3 6.4 6.5 6.6
6.7 6.7 6.7 6.9 7.0 7.0 7.0 7.1 7.2 7.2
7.4 7.5 7.7 7.7 7.8 8.0 8.1 8.1 8.3 8.7
A)
35)
B)
C)
D)
Find the indicated probability.
36) A die with 6 sides is rolled. What is the probability of rolling a number less than 5?
5
2
1
A)
B) 4
C)
D)
6
3
6
Estimate the probability of the event.
37) Of 1982 people who came into a blood bank to give blood, 340 people had high blood pressure.
Estimate the probability that the next person who comes in to give blood will have high blood
pressure.
A) 0.172
B) 0.091
C) 0.14
D) 0.223
Find the indicated complement.
38) If P(A) = 1 , find P(A).
7
A)
6
7
36)
37)
38)
B) 0
C)
8
1
8
D)
7
1
Find the indicated probability.
39) If you pick a card at random from a well shuffled deck, what is the probability that you get a
face card or a spade?
1
11
25
9
A)
B)
C)
D)
22
26
52
26
39)
40) A card is drawn from a well-shuffled deck of 52 cards. Find P(drawing an ace or a 9).
4
2
13
A)
B)
C)
D) 8
13
13
2
40)
41) The table below describes the smoking habits of a group of asthma sufferers.
Occasional Regular
Heavy
Nonsmoker
smoker
smoker
smoker Total
Men
444
37
76
34
591
Women
429
47
86
44
606
Total
873
84
162
78
1197
41)
If one of the 1197 people is randomly selected, find the probability of getting a regular or heavy
smoker.
A) 0.458
B) 0.092
C) 0.135
D) 0.201
42) Find the probability of correctly answering the first 5 questions on a multiple choice test if
random guesses are made and each question has 6 possible answers.
6
5
1
1
A)
B)
C)
D)
5
6
7776
15625
42)
43) A bin contains 78 light bulbs of which 9 are defective. If 3 light bulbs are randomly selected from
the bin with replacement, find the probability that all the bulbs selected are good ones. Round to
the nearest thousandth if necessary.
A) 0.885
B) 0.002
C) 0.721
D) 0.692
43)
44) The table below describes the smoking habits of a group of asthma sufferers.
Light Heavy
Nonsmoker smoker smoker Total
Men
356
50
36
442
Women
418
43
45
506
Total
774
93
81
948
44)
If two different people are randomly selected from the 948 subjects, find the probability that they
are both heavy smokers. Round to six decimal places.
A) 0.0001524
B) 0.007218
C) 0.007301
D) 0.001442
Find the indicated probability. Round to the nearest thousandth.
45) In a batch of 8,000 clock radios 5% are defective. A sample of 14 clock radios is randomly selected
without replacement from the 8,000 and tested. The entire batch will be rejected if at least one of
those tested is defective. What is the probability that the entire batch will be rejected?
A) 0.0500
B) 0.488
C) 0.0714
D) 0.512
9
45)
Find the indicated probability. Express your answer as a simplified fraction unless otherwise noted.
46) The table below shows the soft drinks preferences of people in three age groups.
cola root beer lemon-lime
under 21 years of age 40
25
20
between 21 and 40 35
20
30
over 40 years of age 20
30
35
46)
If one of the 255 subjects is randomly selected, find the probability that the person is over 40
years of age.
1
3
2
1
A)
B)
C)
D)
3
5
5
2
Evaluate the expression.
47) 10P5
A) 5
47)
B) 2
C) 252
D) 30,240
Solve the problem.
48) The library is to be given 3 books as a gift. The books will be selected from a list of 16 titles. If
each book selected must have a different title, how many possible selections are there?
A) 48
B) 560
C) 3360
D) 4096
49) A musician plans to perform 5 selections. In how many ways can she arrange the musical
selections?
A) 25
B) 120
C) 5
D) 720
Identify the given random variable as being discrete or continuous.
50) The number of oil spills occurring off the Alaskan coast
A) Continuous
B) Discrete
51) The pH level in a shampoo
A) Continuous
48)
49)
50)
51)
B) Discrete
Find the mean of the given probability distribution.
52)
x P(x)
0 0.42
1 0.12
2 0.34
3 0.05
4 0.07
A) ! = 1.23
B) ! = 1.13
52)
C) ! = 1.55
10
D) ! = 1.65
Provide an appropriate response. Round to the nearest hundredth.
53) Find the standard deviation for the given probability distribution.
x P(x)
0 0.12
1 0.07
2 0.21
3 0.30
4 0.30
A) " = 1.70
B) " = 2.90
C) " = 1.35
53)
D) " = 1.30
Assume that a researcher randomly selects 14 newborn babies and counts the number of girls selected, x. The
probabilities corresponding to the 14 possible values of x are summarized in the given table. Answer the question
using the table.
Probabilities of Girls
x(girls) P(x) x(girls) P(x) x(girls) P(x)
0
0.000
5
0.122
10
0.061
1
0.001
6
0.183
11
0.022
2
0.006
7
0.209
12
0.006
3
0.022
8
0.183
13
0.001
4
0.061
9
0.122
14
0.000
54) Find the probability of selecting 9 or more girls.
A) 0.122
B) 0.001
54)
C) 0.212
D) 0.061
Assume that a procedure yields a binomial distribution with a trial repeated n times. Use the binomial probability
formula to find the probability of x successes given the probability p of success on a single trial. Round to three
decimal places.
55) n = 6, x = 3, p = 1
55)
6
A) 0.032
B) 0.015
C) 0.029
D) 0.054
Find the indicated probability.
56) The brand name of a certain chain of coffee shops has a 58% recognition rate in the town of
Coffleton. An executive from the company wants to verify the recognition rate as the company is
interested in opening a coffee shop in the town. He selects a random sample of 9 Coffleton
residents. Find the probability that the number that recognize the brand name is not 4.
A) 0.814
B) 0.186
C) 0.0900
D) 0.00148
Find the indicated probability. Round to three decimal places.
57) A machine has 12 identical components which function independently. The probability that a
component will fail is 0.2. The machine will stop working if more than three components fail.
Find the probability that the machine will be working.
A) 0.133
B) 0.795
C) 0.927
D) 0.206
56)
57)
Find the mean, !, for the binomial distribution which has the stated values of n and p. Round answer to the nearest
tenth.
58) n = 40; p = 3/5
58)
A) ! = 24.7
B) ! = 24.3
C) ! = 23.5
D) ! = 24.0
11
Find the standard deviation, ", for the binomial distribution which has the stated values of n and p. Round your
answer to the nearest hundredth.
59) n = 639; p = 0.7
59)
A) " = 15.70
B) " = 14.85
C) " = 11.58
D) " = 9.17
Solve the problem.
60) According to a college survey, 22% of all students work full time. Find the mean for the number
of students who work full time in samples of size 16.
A) 0.2
B) 4.0
C) 3.5
D) 2.8
60)
Using the following uniform density curve, answer the question.
61) What is the probability that the random variable has a value greater than 2?
A) 0.750
B) 0.625
C) 0.700
61)
D) 0.875
Assume that the weight loss for the first month of a diet program varies between 6 pounds and 12 pounds, and is
spread evenly over the range of possibilities, so that there is a uniform distribution. Find the probability of the given
range of pounds lost.
62) Less than 11 pounds
62)
1
1
5
5
A)
B)
C)
D)
6
3
6
7
Find the area of the shaded region. The graph depicts the standard normal distribution with mean 0 and standard
deviation 1.
63)
63)
-3.39 -2.26 -1.13
1.13
A) 0.8907
2.26
3.39
z
B) 0.8485
C) 0.8708
D) 0.1292
64)
64)
-1.84
-0.92
A) 0.1788
0.92
1.84
z
B) 0.3576
C) 0.8212
12
D) 0.6424
Find the indicated z score. The graph depicts the standard normal distribution with mean 0 and standard deviation 1.
65) Shaded area is 0.4013.
65)
z
A) -0.25
B) -0.57
C) 0.57
D) 0.25
66) Shaded area is 0.0694.
66)
z
A) 1.39
B) 1.48
C) 1.26
If z is a standard normal variable, find the probability.
67) The probability that z lies between -2.41 and 0
A) 0.4910
B) 0.0948
68) P(z > 0.59)
A) 0.2224
Find the indicated value.
69) z0.005
A) 2.835
D) 1.45
67)
C) 0.5080
D) 0.4920
B) 0.2776
C) 0.2190
D) 0.7224
B) 2.535
C) 2.575
D) 2.015
68)
69)
Assume that X has a normal distribution, and find the indicated probability.
70) The mean is ! = 60.0 and the standard deviation is " = 4.0.
Find the probability that X is less than 53.0.
A) 0.0802
B) 0.9599
C) 0.5589
70)
D) 0.0401
Solve the problem.
71) The annual precipitation amounts in a certain mountain range are normally distributed with a
mean of 107 inches, and a standard deviation of 12 inches. What is the probability that the mean
annual precipitation during 36 randomly picked years will be less than 109.8 inches?
A) 0.9192
B) 0.5808
C) 0.4192
D) 0.0808
Find the indicated critical z value.
72) Find the critical value z#/2 that corresponds to a 94% confidence level.
A) 1.88
B) 1.555
C) 1.96
13
71)
72)
D) 2.75
Assume that a sample is used to estimate a population proportion p. Find the margin of error E that corresponds to the
given statistics and confidence level. Round the margin of error to four decimal places.
73) 90% confidence; n = 480, x = 120
73)
A) 0.0406
B) 0.0325
C) 0.0387
D) 0.0348
Use the given data to find the minimum sample size required to estimate the population proportion.
74) Margin of error: 0.004; confidence level: 95%; ^
p and ^
q unknown
A) 50,024
B) 60,025
C) 60,018
74)
D) 60,148
Use the given degree of confidence and sample data to construct a confidence interval for the population proportion p.
75) n = 51, x = 27; 95% confidence
75)
A) 0.392 < p < 0.666
B) 0.414 < p < 0.644
C) 0.413 < p < 0.645
D) 0.391 < p < 0.667
Use the confidence level and sample data to find a confidence interval for estimating the population !. Round your
answer to the same number of decimal places as the sample mean.
76) Test scores: n = 75, x = 46.1, " = 5.8; 98% confidence
A) 44.5 < ! < 47.7
B) 45.0 < ! < 47.2
76)
C) 44.8 < ! < 47.4
D) 44.4 < ! < 47.8
Use the given information to find the minimum sample size required to estimate an unknown population mean !.
77) Margin of error: $137, confidence level: 99%, " = $591
77)
A) 71
B) 124
C) 63
D) 50
Use the given degree of confidence and sample data to construct a confidence interval for the population mean !.
Assume that the population has a normal distribution.
78) n = 12, x = 28.3, s = 4.8, 99% confidence
A) 24.01 < ! < 32.59
C) 24.00 < ! < 32.60
78)
B) 24.53 < ! < 32.07
D) 23.91 < ! < 32.69
Use the given degree of confidence and sample data to find a confidence interval for the population standard deviation
". Assume that the population has a normal distribution. Round the confidence interval limits to one more decimal
place than is used for the original set of data.
79) The football coach randomly selected ten players and timed how long each player took to
79)
perform a certain drill. The times (in minutes) were:
9 5 7 12 14
14 5 11 6 9
Find a 95% confidence interval for the population standard deviation ".
A) 2.3 min < " < 5.8 min
B) 0.7 min < " < 2.2 min
C) 2.4 min < " < 5.8 min
D) 2.4 min < " < 6.3 min
Find the P-value for the indicated hypothesis test.
80) A medical school claims that more than 28% of its students plan to go into general practice. It is
found that among a random sample of 130 of the school's students, 32% of them plan to go into
general practice. Find the P-value for a test of the school's claim.
A) 0.1635
B) 0.3461
C) 0.3078
D) 0.1539
14
80)
Solve the problem.
81) A manufacturer finds that in a random sample of 100 of its CD players, 96% have no defects.
The manufacturer wishes to make a claim about the percentage of nondefective CD players and
is prepared to exaggerate. What is the highest rate of nondefective CD players that the
manufacturer could claim under the following condition?
81)
His claim would not be rejected at the 0.05 significance level if this sample data were used.
Assume that a left-tailed hypothesis test would be performed.
A) 96.6%
B) 98.2%
C) 96.5%
D) 98.4%
Determine whether the hypothesis test involves a sampling distribution of means that is a normal distribution,
Student t distribution, or neither.
82) Claim: ! = 981. Sample data: n = 24, x = 972, s = 26. The sample data appear to come from a
normally distributed population with " = 28.
A) Student t
B) Normal
C) Neither
82)
Assume that the data has a normal distribution and the number of observations is greater than fifty. Find the critical z
value used to test a null hypothesis.
83) # = 0.09 for a right-tailed test.
83)
A) ±1.96
B) 1.34
C) ±1.34
D) 1.96
Use the given information to find the P-value. Also, use a 0.05 significance level and state the conclusion about the
null hypothesis (reject the null hypothesis or fail to reject the null hypothesis).
84) The test statistic in a right-tailed test is z = 0.52.
84)
A) 0.6030; fail to reject the null hypothesis
B) 0.0195; reject the null hypothesis
C) 0.3015; reject the null hypothesis
D) 0.3015; fail to reject the null hypothesis
^
Find the value of the test statistic z using z = p - p .
pq
n
85) The claim is that the proportion of drowning deaths of children attributable to beaches is more
than 0.25, and the sample statistics include n = 681 drowning deaths of children with 30% of
them attributable to beaches.
A) 3.01
B) -2.85
C) 2.85
D) -3.01
85)
Construct the indicated confidence interval for the difference between population proportions p1 - p 2. Assume that
the samples are independent and that they have been randomly selected.
86) x1 = 22, n1 = 38 and x2 = 31, n2 = 52; Construct a 90% confidence interval for the difference
between population proportions p1 - p 2.
A) 0.406 < p1 - p2 < 0.752
C) -0.190 < p1 - p2 < 0.156
B) 0.785 < p1 - p2 < 0.373
D) 0.373 < p1 - p2 < 0.785
15
86)
Construct the indicated confidence interval for the difference between the two population means. Assume that the
two samples are independent simple random samples selected from normally distributed populations. Do not assume
that the population standard deviations are equal.
87) Independent samples from two different populations yield the following data. x1 = 236, x2 = 905,
s1 = 88, s2 = 13. The sample size is 381 for both samples. Find the 85% confidence interval for
!1 - !2.
A) -683 < !1 - !2 < -655
B) -670 < !1 - !2 < -668
C) -677 < !1 - !2 < -661
D) -676 < !1 - !2 < -662
87)
Assume that you want to test the claim that the paired sample data come from a population for which the mean
difference is !d = 0. Compute the value of the t test statistic. Round intermediate calculations to four decimal places as
needed and final answers to three decimal places as needed.
88) x 34 39 28 33 27 23 35 33
y 32 35 34 33 28 28 35 32
A) t = 0.690
B) t = -0.185
C) t = -1.480
88)
D) t = -0.523
Given the linear correlation coefficient r and the sample size n, determine the critical values of r and use your finding
to state whether or not the given r represents a significant linear correlation. Use a significance level of 0.05.
89) r = 0.523, n = 25
89)
A) Critical values: r = ±0.396, significant linear correlation
B) Critical values: r = ±0.487, no significant linear correlation
C) Critical values: r = ±0.396, no significant linear correlation
D) Critical values: r = ±0.487, significant linear correlation
Construct a scatterplot for the given data.
x 1 -7 -2 -4 1 5 -6 7 -4 -2
90)
y 7 -1 -7 5 2 3 -2 1 -5 -3
90)
y
10
10 x
-10
-10
16
A)
B)
y
y
10
10
10 x
-10
10 x
-10
-10
-10
C)
D)
y
y
10
10
10 x
-10
10 x
-10
-10
-10
Suppose you will perform a test to determine whether there is sufficient evidence to support a claim of a linear
correlation between two variables. Find the critical values of r given the number of pairs of data n and the significance
level #.
91) n = 14, # = 0.05
91)
A) r = ±0.661
B) r = ±0.532
C) r = 0.532
D) r = 0.553
Is the data point, P, an outlier, an influential point, both, or neither?
92)
y
60
50
40
30
P
20
10
10
20 x
A) Both
C) Outlier
B) Neither
D) Influential point
17
92)
Use the given data to find the equation of the regression line. Round the final values to three significant digits, if
necessary.
93) x 0 3 4 5 12
93)
y 8 2 6 9 12
A) ^
y = 4.98 + 0.725x
B) ^
y = 4.88 + 0.525x
C) ^
y = 4.88 + 0.625x
D) ^
y = 4.98 + 0.425x
18