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Chapter 1
1. To describe a set of numbers, you must provide: (Points: 2)
a. N
b. a measure of central tendency
c. a measure of variability
d. only 1 & 2
e. all of the above
2. According to your textbook, you should predict that everyone will score precisely at
the mean: (Points: 2)
a. because most people score right at the mean
b. even if no one can possibly score at the mean
c. because the mean is a least squares prdictor
d. only 2 and 3 are true
e. none of the above
3. The sum of the deviations around the mean: (Points: 2)
a. is always positive
b. is always negative
c. is sometimes positive and sometimes negative
d. none of the above (1, 2, or 3) is true
4. According to class discussion, which is the most important measure of central
tendency for the behavioral sciences? (Points: 2)
a. the mean
b. the median
c. the mode
d. all three are equally important
5. According to class discussion, the mean, the median, and the mode: (Points: 2)
a. are equally important in the behavioral sciences
b. are all measures of variability
c. both 1 & 2 are true
d. neither 1 nor 2 are true
6. Al scores 14, Barry scores 26, Charlie scores 22, Dan scores 15, and Ed scores 23.
What is the sum of squared deviations around the mean? (Points: 2)
a. 100
b. 110
c. 120
d. 130
e.
none are within 10 points
7. Alice scores 10, Barbara scores 4, Celia scores 3, Donna scores 8, and Emma scores 5.
What is the variance? (Points: 2)
a. 6.60
b. 6.80
c. 7.00
d. 7.10
e. none are within .10 points
8. Arnold scores 910, Betty scores 902, Cal scores 920, Denise scores 912, and Ellen
scores 911. What is the standard deviation? (Points: 4)
a. 5.50
b. 6.00
c. 6.20
d. 6.40
e. none is within .10 points
Quiz 1 answers: 1. All of the above 2. both 2 and 3 are true 3. none of the above are
true 4. the mean 5.are all measures of variability 6. 110 7. 6.80 8. None
Chapter 2
1. A set of scores that range from 1 to 40 were divided into 8 equal class intervals (1-5, 6-10,
11-15, …36-40. John notices something strange with this set of class intervals. When he
subtracts the lower from the upper class boundary, he gets 4 in each case (for example, 106=4). Yet there are 5 possible scores between 6 and 10 (6,7,8,9, and 10). What is the problem?
(Points: 2)
a. He is looking at the apparent rather than real class limits
b. John is worrying about nothing. He has just subtracted incorrectly
c. The real limits of an interval are unclear
d. This is a discrete variable so it behaves in strange ways
e. None of the above is correct
2. A set of scores that appear as integers and that range from 1 to 40 were divided into 8 equal
class intervals (1-5, 6-10, 11-15, …36-40). What are the real limits of the class that goes from 6
– 10? (Points: 2)
a. 5.50000… and 10.50000…
b. 6.00 and 10.00
c. 5.5 and 10.4
d. 5.0 and 11.0
e. None of the above is correct
3. John’s teacher has just completed a survey concerning attitudes about the student’s
background. Students were asked what continent their grandparents had been born on. The
questions were answered by circling a 1 for North America, 2 for South America, 3 for Africa, 4
for Asia, 5 for Europe, 6 for Other (e.g., Australia), 7 if ones grandparents had been born on two
or more different continents and 8 if you did not know on which continent one or more of your
grandparents were born. This measure is an example of what kind of variable? (Points: 2)
a. Dependent
b. Independent
c. Continuous
d. Discrete
e. It is impossible to tell
4. Frequency distributions can be represented as: (Points: 2)
a. Scatterplots
b. Tables
c. Bar graphs
d. Only 2 and 3 are correct
e. All of the above (1, 2, and 3) are correct
f. None of the above (1, 2, or 3) are correct
5. Bar graphs: (Points: 2)
a. Have shapes similar to the shape of the tally
b. Are true graphs
c. Are really meant for continuous, not discrete, variables
d. Only 1 and 2 are correct
e. All of the above (1, 2, and 3) are correct
f. None of the above (1, 2, or 3) are clearly correct
6. A researcher gathers life satisfaction scores from the residents of a nursing home on a scale
that goes from 0=totally dissatisfied and miserable about my life to 10=totally satisfied and
happy with my life. Of the residents 1 scored zero, 0 scored one, 7 scored two, 3 scored three,
4 scored four, 9 scored five, 7 scored six, 2 scored seven, 6 scored eight, 7 scored nine, and 5
scored ten. What is the cumulative relative frequency of a score of 8? (Points: 3)
a. 0.755
b. 0.805
c. 0.765
d. 0.800
e. None of the above are correct
7. A researcher sets up a series of mutually exclusive and exhaustive class intervals for a data
set. Class intervals go from 0-9, 10-19, 20-29, 30-39, 40-49, 50-59, and 60-69. What are the
real limits of the interval that goes from 30-39? (Points: 2)
a. 29.00 - 39.00
b.
c.
d.
e.
29.45 - 39.45
29.25 - 39.50
29.50 - 39.50
None of the above are correct
8. A researcher determines that the expected frequency of the class interval that goes from 610 is 0.850. Of 200 people, how many should score 6, 7, 8, 9, or 10? (Points: 2)
a. 120.00
b. 130.00
c. 150.00
d. 170.00
e. None of the above are correct
9. Assume a rectangular distribution with 8 equally likely mutually exclusive and exhaustive
class intervals forming the distribution. Of 80 people, how many should score in each of the
intervals? (Points: 3)
a. 25.00
b. 30.00
c. 15.00
d. 10.00
e. None of the above are correct
Quiz 2 answers: 1. He is looking at apparent rather than real class limits.
2. 5.500000… and 10.500000… 3. Discrete 4. Tables and Bar Graphs, so only 2 & 3
is correct. 5. Have shapes similar to the shape of the tally 6. 0.765 7. 29.50 – 39.50
8. 170.00 9. 10.00
Chapter 3
Which of the following equations is correct? (Points: 2)
a. If Z is negative: Percentile Rank = 100(twice the Area from the mean to Z-.5000)
b. If Z is negative: Percentile Rank = 100(Area from the mean to Z)
c.
If Z is positive: Percentile Rank = 100(twice the Area from the mean to Z)
d. Only 1 and 3 are correct
e. All of the above (1, 2, and 3) are correct
f. None of the above (1, 2, or 3) is correct
2. X1 and X2 are scores on the same normal curve with mean = 100, standard deviation = 10. We
know that X1 = 110. We also know that the proportion of scores that fall between X 1 and X2 is
.5000. Which of the following is true about X2? (Points: 2)
a. We can find X2 with the help of the Z table
b. X2 could be more than one of two possible scores
c. X2 is below the mean
d. Only 1 and 3 are true
e. None of the above (1, 2, or 3) is true
3. Which of the following is/are characteristic of normal curve? (Points: 2)
a. The proportion of scores between Z scores of 0.00 and +1.00 is smaller than the
proportion between Z scores of 0.00 and -1.00
b. The proportion of scores between Z scores of -0.50 and +0.50 is larger than the
proportion between Z scores of 0.00 and -1.00
c. The proportion of scores between Z scores of +2.00 and +3.00 is larger than the
proportion between Z scores of 0.00 and +0.50
d. Only 1 and 2 are true
e. Only 1 and 3 are true
f. All of the above (1, 2, and 3) are true
4. The critical values of the Z curve (Points: 2)
a. Define the points where 90% and 95% of the scores are in the body of the curve
b. Define the point where .5% and 2.5% of the scores are in each tail of the curve
c. Are 1.000, 2.000, and 3.000
d. Only 1 and 2 are correct
e. All of the above (1, 2, and 3) are correct
f. None of the above (1, 2, or 3) is correct
5. The critical values of the Z curve (Points: 2)
a. Are 1.960 and 2.000
b. Are 1.960 and 2.576
c. Are 1.960 and 3.000
d. Both 1 and 2 might be considered correct
e. Both 1 or 3 might be considered correct
f. None of the above (1, 2, or 3) is correct
6. 30 people take a test. How many should obtain Z scores between -1.14 and +0.43? (Points:
2)
a. 6.20
b. 3.10
c. 4.45
d. 16.18
e.
None of the above are correct
7. 300 people take a test. How many should obtain Z scores between +0.5 and 1.40? (Points: 2)
a. 20.16
b. 40.64
c. 89.48
d. 68.31
e. None of the above are correct
8. 350 people take a test. How many should obtain Z scores above 1.54? (Points: 2)
a. 21.63
b.
5.36
c. 15.62
d.
4.98
e.
None of the above are correct
9. 100 people take a test. How many should obtain Z scores above -0.33? (Points: 2)
a. 12.93
b. 87.07
c. 37.07
d. 62.93
e. None of the above are correct
10. Someone scores at the 50th percentile. Which of the following Z scores might she have
obtained? (Points: 2)
a. 5.00
b. 1.64
c. 0.00
d. -1.64
e. None of the above are correct
Quiz 3 answers: 1. None of the above 2. We can find X2 with the help of the Z table and
we know that X2 is below the mean, thus 1 and 3 are true. 3. the proportion of scores
between Z= -.50 and +.50 is larger than the proportion between 0.00 and –1.00. 4. Define
the point where .5% and 2.5% of the scores are in each tail of the curve. 5. Critical values
are 1.960 and 2.576 6. 16.18 7. None are correct 8. 21.63 9. 62.93 10. Z=0.00
Chapter 4
1. In terms of absolute distance from the mean, which pairs of scores are similar? (Notice that we
are only talking about absolute difference; direction from the mean is irrelevant in this question.)
(Points: 2)
a. A GRE score of 700 and an IQ score of 70
b. An IQ score of 120 and a normal score of 20
c. A GRE score of 600 and a Z score of 0.50
d. Both 1 and 2 but not 3
e. Both 1 and 3, but not 2
f. All of the above (1, 2, and 3) are similar
2. You take 200 random samples from a population. According to your book and class
discussion, which of the following should occur as the size of each and every sample increases?
(Points: 2)
a. The mean of each sample tends to get closer and closer to mu
b. The distribution of sample means gets closer and closer to a normal curve
c. The standard error of the sample means gets closer and closer to sigma divided by 200
d. Both 1 and 2 should occur
e. Both 2 and 3 should occur
f. All of the above (1, 2, and 3) should occur
3. Which of the following is (are) correct statement(s) about the standard error of the mean
(sigmaX-Bar)? (Points: 2)
a. The average unsquared difference of sample means from each other is called the
standard error of the mean
b. SigmaX-Bar stays the same no matter what the size of the sample
c. SigmaX-Bar is the average unsquared distance of sample means from mu
d. All of the above (1, 2, and 3) are correct
e. None of the above (1, 2, or 3) is correct
4. To find the number of scores between two Z scores on the same side of the mean (Points: 2)
a. You look up the area of the curve between mu and each Z score and then add them
together and multiply by N
b. You look up the area of the curve between mu and each Z score and then subtract the
smaller area from the larger area and multiply the result by N
c. You add the two Z scores together and then look up the result in the table and divide by N
d. You subtract the smaller of the two Z scores from the larger and multiply by N
e. None of the above (1, 2, or 3) will provide the right answer
5. Z scores are defined by the formula: (Points: 2)
a. Z = (X-sigma)/mu
b. Z = (X-mu)/sigma2
c. Z = (X-mu)/sigma
d. Z = (X –mu)/mu
e.
None of the above
6. On the verbal part of the SAT, John gets a raw score of 59. The mean is 65.00 with a standard
deviation of 2 points. Translate John’s raw score to a verbal SAT score. (Points: 1)
a. 200
b. 300
c. 250
d. 750
e. None of the above are correct
7. Jenny has an I.Q. of 93. What is her percentile rank? (Points: 1)
a. 32
b. 37
c. 40
d. 43
e. None of the above are correct
8. 700 people take a test. The mean of the raw scores is 67.00 with a standard deviation of 9.00.
How many should obtain raw scores between 52.00 and 61.00? (Points: 2)
a. 84.68
b. 108.68
c.
96.68
d.
1.76
e. None of the above are correct
9. A research group studying a very large population learns that the mean of the population is
20.00 and sigma = 5.00 . They then embark on a massive project involving 180 samples, each
with 49 participants (n= 49 ). How many of the 180 samples will obtain average scores between
22.00 and 26.00? (Points: 3)
a. 0.47
b. 60.16
c. 179.53
d. 140.18
e. None of the above are correct
10. A research group studying a very large population learns that the mean of the population is
27.00 and sigma = 8.00. Which of the answers below defines the CI.95 for samples of size 9?
(Points: 3)
a. 19.20 < X < 50.80
b. 22.20 < X < 47.80
c. 25.20 < X < 44.80
d. 28.20 < X < 41.80
e. None of the above are correct
Chapter 4 answers:1. A GRE score of 700 and an IQ of 70 are both 2 standard deviations
from the mean. 2. Sample means get closer to mu and the distribution of sample means
gets closer to normal. So both A and B are correct. 3. sigmaX-bar is the average unsquared
distance of sample means from mu. 4. Subtract the smaller area from the larger and
multiply by N 5. Z = (X-mu)/sigma 6. 200 7. 32nd percentile 8. Answer is 142.73 so
none of the listed answers is close to correct 9. 0.47 10. 22.77 and 32.23 are the limits of
the 95% confidence interval, so none of the answers is correct.