Download Final Exam Name: MAT 118, Spring 2013 Part 1: Multiple Choice

Final Exam
MAT 118, Spring 2013
Name:
Part 1: Multiple Choice
Please select the best answer and bubble in your answer on the scantron sheet.
On July 15, 2004, the Harris Poll released the results of a study asking whether people favored or
opposed abolishing the penny. Of a national sample of 2136 adults, 59% opposed abolishing the
penny.
1.
What are the observational units (individuals) in the study?
(a) the number of people who would abolish the penny in the entire population
(b) the number of people who would abolish the penny in the sample
(c) the people who responded to the poll
(d) the percent of people who oppose abolishing the penny
2.
Suppose that the observational units (individuals) in a study are Pennsylvania high
schools. Which of the following is not a valid variable?
(a.) whether or not the school has an animal for its mascot
(b.) proportion of students scoring proficient or better on the PSSA at each school
(c.) total number of students at each school
(d.) number of high schools in Pennsylvania which have indoor pools
For questions 3 and 4 use the following situation:
3.
Suppose that 80% of all American students actually send a card to their mother on
Mother's Day. You select a simple random sample of 400 American college students and
determine the proportion of them who send a card to their mother on Mother's Day.
Suppose further that in the random sample of 400 students, 300 or 75% of them send a
card to their mothers.
(a.)
(b.)
(c.)
(d.)
4.
80% is a parameter, 75% is a statistic.
75% is a parameter, 80% is a statistic.
Both 75% and 80% represent statistics.
Both 75% and 80% represent parameters.
Which of the following is true?
(a.)
the 400 college students are the population
(b.)
the sample size is 400
(c.)
all college students in the world are the sample
(d.)
the sample is the 300 students who send a card
5.
You are concerned that your employees have little saved for retirement. You conduct a
survey of your 100,000 employees using a simple random sample of size 47. You find
that the mean of the savings of this sample of employees is $40,000 with standard
deviation of $3,000.
This is an example of an…
(a) observational study since subjects are randomly assigned to groups
(b) observational study since it is based on taking a sample of a population without
intervening
(c) experiment since subjects are randomly assigned to groups
(d) experiment study since it is based on taking a sample of a population without
intervening
6.
Researchers concerned about the effects of excessive television viewing on students
school performance are planning to conduct a study. Which of the following is true?
(a.) This study would be considered an observational study if they assigned one group of
students to watch 4 hours of television each day and another group to not watch any
television.
(b.) This study would be considered biased if they assigned one group of students to
watch 4 hours of television each day and another group to not watch any TV.
(c.)This study would be considered an experiment if they assigned one group of students
to watch 4 hours of television each day and another group to not watch any TV.
(d.) This study would be considered an experiment if they took a random sample of
students, recorded their grades and the number of hours of television they watched.
7.
A survey is to be undertaken of recent nursing graduates in order to compare the starting
salaries of women and men. For each graduate, three variables are to be recorded (among
others) sex, starting salary, and area of specialization.
(a) Sex and starting salary are explanatory variables; area of specialization is a response
variable
(b) Sex is an explanatory variable; starting salary and area of specialization are response
variables.
(c) Sex is an explanatory variable; starting salary is a response variable; area of
specialization is a possible confounding variable
(d) Sex is a response variable; starting salary is an explanatory variable; area of
specialization is a possible confounding variable
(e) Sex and area of specialization are response variables; starting salary is an explanatory
variable.
8.
A study was conducted to see if Smartfood Popcorn makes people smarter. A group of 50
participants in the study were divided into two groups. One group received Smartfood
Popcorn before taking a spelling test, and the other took the test without first getting
popcorn. The Smartfood experiment would be said to take into account the principle of
blindness if ___________, and it could be said to be double-blind if _____________.
(a.) the subjects are randomly assigned to either eat Smartfood or not;
those evaluating the subjects are blindfolded
(b.) the subjects are not aware of which treatment group they are in;
those evaluating the subjects are not aware of which treatment group received Smartfood
(c.) the subjects are selected at random from the population;
those evaluating the subjects are not aware of which treatment group the subjects are in
(d.) the subjects are not aware of which treatment group they are in;
the two treatment groups are never come in contact
9.
An experiment is conducted to determine if the use of certain specified amounts of a drug
will increase the IQ scores for students in the fifth grade.
In this experiment, IQ serves as:
(a.) a response variable
(b.) an explanatory variable
(c.) a placebo variable
(d.) a control variable
10.
A new headache remedy was given to a group of 25 subjects who had headaches. Four
hours after taking the new remedy, 20 of the subjects reported that their headaches had
disappeared. From this information you should conclude:
(a) that the remedy is effective for the treatment of headaches.
(b) nothing, because the sampling method is biased.
(c) nothing, because there is no control group for comparison.
(d) that the new treatment is better than aspirin.
11.
Researchers have observed that drinking red wine seems to lead to fewer men having
heart attacks. More recently, others have noted that drinking red wine leads to
headaches and people with headaches tend to take aspirin. Furthermore, aspirin is
known to reduce the changes of having heart attacks. Given these facts, the relationship
between drinking red wine and having heart attacks would be best described as being due
to:
(a.) cause-and-effect.
(b.) strong correlation.
(c.) a lurking variable.
(d.) placebo effect.
12.
There is a relationship between the number of drownings per day and ice
cream sales. This is an example of an association likely caused by:
(a) coincidence
(b) the fact that ice cream causes drownings
(c) confounding or lurking variable
(d) the fact that drowning cause eating ice cream
13.
An experiment was designed to investigate the effect of the amount of water and seed
variety upon subsequent growth of plants. Each plant was potted in a clay plot, and a
measured amount of water was given weekly. The plants that were assigned to receive
more water had all been placed closer to a window that the ones that received less water.
The height of the plant at the end of the experiment was measured. Which of the
following is NOT correct?
(a) The response variable is the plant height.
(b) The explanatory variables are the amount of water and seed variety.
(c) The seeds should be randomly selected from the population of all seed varieties rather
than randomly assigned to receive more or less water.
(d) The effect of the amount of water was confounded by the effect of being near the
window
14.
The histogram displays the percent of overweight adults in each state. Which of the
following is NOT true?
(a) The distribution is symmetric
(b) In a typical state about 37% of the people are overweight
(c) 14 states have less than 36% overweight
(d) 2 states have 11% overweight
The following side-by-side boxplots represent the rushing yards gained by the starting running
backs in the opening game. Compare and contrast their performance.
15.
Carson runs further than 5 yards about what percent of the time?
(a) 15%
(b) 25%
(c) 50%
(d) 75%
16.
_____ tends to run further. _____ is more
consistent.
(a) Asika; Asika
(b) Asika; Carson
(c) Carson; Asika
(d) Carson; Carson
17.
Based on the dotplots of February temperatures for three cities, answer the following
which of the following is NOT true?
(a) San Luis Obispo experienced generally
higher temperatures than Sedona and
Lincoln
(b) The distribution of temperatures for
Sedona is skewed toward lower values
(c) The city with the most consistent
temperatures was Sedona
(d) The temperatures in Lincoln tend to be
higher than those in Sedona
18.
The measure of spread which is resistant to extreme scores on the higher or lower end of
a distribution is the:
(a) range.
(b) mean.
(c) standard deviation.
(d) IQR
19.
Making the largest number in a data set much larger will increase the ______ but not
change the _________.
(a) median; mean
(b) mean; standard deviation
(c) standard deviation; IQR
(d) IQR; median
20.
Which of the following is NOT a measure of center?
(a.) mean
(b.) median
(c.) mode
(d.) standard deviation
21.
The dotplot to the right compares
some systolic and diastolic blood
pressure measurements. Which of
the following is NOT true?
(a.) systolic blood pressure tends
to be higher than diastolic blood
pressure
(b.) systolic blood pressure
reading tend to be above 100
(c.) every systolic reading is
higher than every diastolic reading
(d.) diastolic blood pressure
readings tend to be below 100
22.
Calculate the range and the IQR for the data set: {1,2,3,4,5,6,7,8}
(a.) 7 and 4
(b.) 8 and 3
(c.) 8 and 1
(d.) 6 and 5
23.
According to the empirical rule, for any mound-shaped distribution, about 95% of the
data will be…
(a) within one standard deviation of the mean
(b) within two standard deviations of the mean
(c) within three standard deviations of the mean
(d) within four standard deviation of the mean
24.
If the mean of a distribution of test score is 70 and the standard deviation is 10, the
empirical rule predicts that about 68% of the students scored between…
(a) 60 and 80
(b) 70 and 80
(c) 50 and 90
(d) 60 and 90
Consider the following two-way table showing the favorite leisure activities for 50 adults.
Dance
Sports
TV
Total
Men
2
10
8
20
Women
16
6
8
30
Total
18
16
16
50
25.
What proportion of people preferring Dance are woman, and what proportion are men?
(a.)
89%, 11%
(b.)
40%, 60%
(c.)
36%, 64%
(d.)
50%, 50%
26.
What is the conditional distribution of the variable Gender for people preferring TV?
(a.)
89%, 11%
(b.)
40%, 60%
(c.)
36%, 64%
(d.)
50%, 50%
27.
What is the marginal distribution of the variable Gender?
(a.)
89%, 11%
(b.)
40%, 60%
(c.)
36%, 64%
(d.)
50%, 50%
Consider the two-way table below based on a class of 30 students and their responses as to
whether or not they own a cat and whether or not they own a dog:
28.
Has a Cat
No Cat
Total
Has a Dog
8
4
12
No Dog
2
16
18
Total
10
20
30
Describe the relationship between having a cat and having a dog in this class.
(a.) whether a student has a dog is not related to whether the student has a cat
(b.) Students with a cat are more likely to also have a dog than students without a cat
(c.) Students with a dog are less likely to have a cat than students who do not have a dog
(d.) Most students have either a cat or a dog or both
29.
The following is a scatterplot displays SAT math scores for each state versus the percent
of students taking the exam.
Which best describes the relationship?
(a.)
positive, strong, linear
(b.)
negative, moderate, linear
(c.)
negative, strong, non linear
(d.)
no relationship
30.
The correlation between the Governor’s salary in each state and the median home value
in the state is positive. Therefore, we can conclude that…
(a.)
states with above average Governor’s salaries tend to have below average home
values.
(b.)
states with below average Governor’s salaries tend to have above average home
values.
(c.)
states with above average Governor’s salaries tend to have above average home
values.
(d.)
there is no relationship between housing values and salaries of Governors.
31.
If a correlation coefficient between Age and Coolness Rating is -0.70, then:
(a) A person’s Age is usually less than the person’s Coolness Rating.
(b) A person’s Age is usually more than the person’s Coolness Rating.
(c) Below average Ages tend to be associated with below average values of Coolness.
(d) Below average Ages tend to go with above average values of Coolness.
32.
Below is the Statcrunch output for a regression run on “Airfare” (in dollars) versus
“Distance” (in miles) for a set of data for flights between 12 cities.
Simple linear regression results:
Dependent Variable: Airfare
Independent Variable: Distance
Airfare = 83.26736 + 0.11737509 Distance
Sample size: 12
R (correlation coefficient) = 0.795
R-sq = 0.63200194
Estimate of error standard deviation: 37.827023
The slope of the regression equation indicates that…
(a)
There is a strong negative linear relationship
(b)
An additional mile tends to cost about 11.7 cents
(c)
A trip of 0 miles costs .117 dollars
(d)
None of the above
33.
The “line of best fit” under the least squares criterion is the one which…
(a)
minimizes the sum of all the perpendicular distances from the points to the line.
(b)
has the greatest sum of squared errors in predictions.
(c)
has the smallest sum of squared residuals
(d)
has the smallest average residual
34.
Which is a correct interpretation of the Law of Large Numbers?
(a.)
If you flip a coin 10 times and get 9 heads, we expect to get tails on the next toss.
(b.)
If you flip a coin a small number of times you are more likely to get close to 50%
“heads” than if you flip a coin a large number of times.
(c.)
If you flip a coin twice and get “heads” both times, the next flip will most likely
come up “tails”
(d.)
If you flip a coin 50 times, you probably won’t get exactly 25 “heads” but you are
likely to get somewhat close to 50% “heads”
35.
When rolling a pair of 6-sided dice, what is the probability of rolling a sum of 6 or 7?
(a.) 1/6
(b.) 3/14
(c.) 5/12
(d.) 11/36
36.
Tina has 5 red, 6 blue, 3 white, and 4 orange marbles. All marbles are put in a sack and
one marble is selected at random. Compute the probability of drawing a red marble and
the probability of drawing a blue or white marble.
(a.) 4/19; 9/20
(b.) 3/10; 11/20
(c.) 5/18; 1/2
(d.) 9/21; 7/18
37.
In a basketball one-and-one situation. If a player makes the first foul shot, she gets
another foul shot. If she misses it , she does not get to shoot again. (So a player can score
0,1, or 2 points in a one-and-one situation.) Suppose Liz has a 70% chance of making
each foul shot. What is the probability that she scores exactly one point in a one-and-one
situation?
(a.) 70%
(b.) 9%
(c.) 49%
(d.) 21%
38.
A drawer contains 5 black socks and 3 blue socks. If you reach into the drawer without
looking and pull out two socks, what is the probability that you get a matching pair?
(a.) 21/56
(b.) 13/28
(c.) 4/56
(d.) ½
39.
The binomial probability formula is P(X = k) = nCk × pk (1- p)n-k . Which of the
following sets of values when substituted into the formula above gives the probability of
getting 6 sixes in 10 rolls of a die?
(a) n = 4, p = 10, k = 1/6
(b) n = 10, p = 1/6, k = 4
(c) n = 10, p = 1/6, k = 6
*there was an error on this one.
(d) n = 4, p = 1/6, k = 10
40.
Which of the following is not a situation where the binomial probability formula should
be applied?
(a.)
(b.)
(c.)
(d.)
A coin is flipped 20 times. What is the probability of getting 5 or more heads?
What is the probability that the first 6 occurs on the 5th roll of a six-sided die?
What is the probability that Liz will make exactly 3 out of 5 shots if she has a
70% chance of making each shot and we assume independence?
A bag contains 6 marbles of which two are green. A marble is selected at random
from the bag, the color is noted, and the marble is returned to the bag. Repeating
this action 15 times, what is the probability of getting 5 or fewer green marbles?
41.
Compute the z-score for a score of 78 on a test with the following summary statistics:
min = 20, Q1 =70, med = 75, Q3 = 76, max = 100, s = 4, x = 70
(a) z = 2
(b) z = 2.5
(c) z = 0
(d) z = 7
42.
A negative z-score indicates…
(a) that someone made a computational error
(b) that the mean is a negative number
(c) that the distribution is skewed toward lower values
(d) that the item in question is below the mean
43.
Suppose a medical experiment randomly assigns patients with a certain condition to
either receive an “old” treatment or a “new” treatment. The experimenters are interested
in whether the new treatment works better than the old treatment.
Which of the following would be an appropriate null hypothesis?
(a.)
The new treatment works better than the old treatment
(b.)
The new treatment works the same as the old treatment
(c.)
The old treatment works better than the new treatment
(d.)
Neither the old or new treatments work.
44.
Which of the following is the best explanation of a null hypothesis, Ho, in a statistical
test.
(a) a statement of what we are trying to prove in an experiment
(b) it is usually a statement that “there really is a difference”
(c) a neutral assumption made for the sake of argument that the researcher tries to
disprove based on conflict with the observed data
(d) it is the hypothesis that the data cannot be explained by random variability
45.
A p-value of 0.11 would indicate…
(a) that someone made a computational error
(b) strong evidence against the null hypothesis
(c) that the alternative hypothesis must be false
(d) that we should fail to reject the alternative hypothesis at a .05 significance level

46.
In an experiment to study attempting to identify factors which can influence people’s
responses to survey questions, subjects were randomly given one of the two following
statements and asked whether they agree or disagree:
A: “Individuals are more to blame than social conditions for crime and lawlessness in this
country.”
B: “Social conditions are more responsible than individuals for crime and lawlessness in
this country.”
The responses are summarized below:
Blame Individuals Blame Social Conditions Total
A
282
191
473
B
204
268
472
Total
486
459
945
Statistic
Chi-square
DF
Value
P-value
1 25.4347 <0.0001
Based on the p-value, which of the following is an appropriate conclusion for a chisquare test (a procedure we have not studied) of the null hypothesis that the wording of
the question did not influence the responses:
(a.)
(b.)
(c.)
(d.)
47.
Accept the null hypothesis. There isn’t sufficient evidence to demonstrate that the
wording of the question had an effect.
Reject the null hypothesis. There is strong evidence that people were influenced
by a tendency to agree with the researcher
Fail to reject the null hypothesis. People were more likely to disagree than to
agree with whichever statement was given.
Reject the alternative hypothesis. There no evidence suggesting that the wording
of the question influenced responses.
Roberto suspects that his brother’s coin is biased towards heads. He flips the coin a large
number of times and records the results. Suppose that the number of “heads” he got
differs from the expected number of “heads” from a fair coin such that the p-value in a
statistical test of significance is 0.04. Which of the following is NOT a correct
interpretation of this p-value?
(a) In only 4 random samples in one hundred would we see such a large difference
between the observed and expected numbers of heads when flipping a fair coin.
(b) The null hypothesis of the test should be rejected at the .05 significance level.
(c) The coin is biased such that it comes up “heads” less than 4% of the time.
(d) If Roberto’s brother’s coin is fair, the probability of observing such a large difference
between the observed and expected numbers of “heads” is fairly small.
48.
Researchers would like to understand how pet ownership is related to longevity. Which
of the following is true?
(a.) This study would be considered an observational study if they randomly assigned
subjects to either receive a pet or not.
(b.) It would only be appropriate to conclude that there is a cause and effect relationship
based on the results of an experiment rather than an observational study
(c.)This study would be considered an experiment if they took a random sample of pet
owners and noted whether or not they owned a pet
(d.) It is only possible to infer a cause and effect relationship if the correlation is close to
1 or -1.
49.
In order to test the hypothesis that the average body temperature of a healthy adult is 98.6
degrees, a random sample of 100 healthy adults was selected from the population of all
healthy adults. Suppose that the population standard deviation for body temperatures is 2
degrees and that the sample mean body temperature was 98.3.
Find the z statistic that could be used for a one-sample z-test in this situation.
(a) 1.5
(b) 1.89
(c) 2.001
(d) 2.132
50.
Assume that the amount of time eighth graders play video games each day has a normal
distribution with standard deviation 5.8 hours. In a recent study of a random sample of 22
eighth graders, the mean number of hours per week that they played video games was 19.
Construct a 90% confidence interval for the population mean, μ.
(a)
(19.62, 23.12)
(b)
(17.57, 21.63)
(c)
(5.87, 7.98)
(d)
(18.63, 20.89)