STAT 3090
Test #1 (Version B)
Student’s Printed Name: __________________________________
Instructor: ___________________________
Spring 2016
CUID:__________________
Time/Section # :________
You are permitted to use a calculator on all portions of this test. You are not allowed to use any textbook, notes, cell
phone, or laptop on any portion of this test. All devices must be turned off while you are in the testing room. During
this test, any communication with any person (other than the instructor or test proctor) in any form, including
written, signed, verbal, or digital, is understood to be a violation of academic integrity. No part of this test may be
removed from the testing room.
Read each question very carefully. In order to receive full credit for the free response portion of the test, you must:
1. Show legible and logical (relevant) justification which supports your final answer.
2. Use complete and correct mathematical notation.
3. Include proper units, if necessary.
You have 90 minutes to complete the entire test.
On my honor, I have neither given nor received inappropriate or unauthorized information at any time
before or during this test.
Student’s Signature: ________________________________________________
Do not write below this line.
Free Response Problem Points Possible Points Earned
1
4
2
4
3a
4
3b
4
4
6
5a
4
5b
4
5c
1
6a
4
6b
4
7
1
Free Response Total
40
Multiple Choice
60
Correct Scantron
1
Test Total
100
Page 1 of 11
STAT 3090
Test #1 (Version B)
Spring 2016
Part I: Multiple Choice. There are 20 multiple choice questions. Solve each question using the available space
for scratch work. Decide which is the best of the choices given and fill in the corresponding oval on the
provided scantron using a #2 pencil. For your own record, also circle your choice on your test since the
scantron will not be returned to you. Only the responses recorded on your scantron sheet will be graded. Each
multiple choice question is worth 3 points.
1. The histogram below presents a distribution of tuition ($) in a group of colleges.
Decide what statement is false.
Histogram of Tuition ($)
6
Frequency
5
4
3
2
1
0
15000
20000
25000
30000
35000
40000
Tuition ($)
a)
b)
c)
d)
The histogram is skewed to the left.
No college has tuition lower than $15,000.
Tuition of 10 colleges is reported.
There are more than 5 colleges with tuition above $30,000.
2. John and Paul are two students who buy groceries in a local store independently of one another. For late
Friday shopping, there is 0.8 probability that John would shop, while there is a 0.4 probability that Paul
would be in the store. For late Friday shopping, what is the probability that at least one of them will be in
the store?
a)
b)
c)
d)
0.68
0.12
0.88
0.32
3. Plain M&Ms candies can be one of 6 colors: yellow, red, orange, blue, green and brown. The makers of M&Ms
report that plain M&Ms are composed of 15% yellow, 10% red, 20% orange, 25% blue, and 15% green. What is the
probability that a randomly selected M&M is brown or red?
a)
b)
c)
d)
5%
10%
15%
25%
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STAT 3090
Test #1 (Version B)
Spring 2016
Copiers Etc. collects data on the number of copiers sold each day. The number of copiers sold on a
randomly selected day is displayed in the boxplot below.
Use the following box plot to answer Questions 4 and 5.
4. Which of the following is the interquartile range for copiers sold per day?
a)
b)
c)
d)
1
4
5
8
5. What percentage of days were the number of copiers sold is greater than 1?
a)
b)
c)
d)
25%
50%
75%
0%
6. Two distributions A and B are displayed on the same graph. If the distribution A is right skewed, the distribution B is
left skewed, and the mean of A is lower than the mean of B, which of the following statements is not true?
a)
b)
c)
d)
The median of A is lower than the median of B
The mean of B is lower than the median of A.
The mean of A is lower than the median of B.
The mean of B is lower than the median of B.
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STAT 3090
Test #1 (Version B)
Spring 2016
The table below summarizes the number of rotary oil drilling rigs in certain districts in Texas as of January 15, 2016.
TEXAS
DISTRICT
DISTRICT 1
DISTRICT 2
DISTRICT 3
DISTRICT 4
DISTRICT 5
Rotary Rigs
Running
29
33
18
12
2
7. What is the relative frequency for the number of rotary rigs running in District 2?
a)
b)
c)
d)
3
18/94
33/94
16.56
8. Consider the following random experiment: Toss a coin two times and observe the number of heads. Which of the
following represents the correct sample space for this experiment?
a)
b)
c)
d)
{T, H}
{TT, HH, TH, HT}
{HH, TH, TT}
None of the above
9. A data set consists of five numbers: -5.0, -3.5, 0, 4.0 and a missing 5th number. From these five data points, which of
the following can never be greater than zero?
a)
b)
c)
d)
The interquartile range
The median
The sample standard deviation
The mean
10. Given the following: P(A) = .75, P(B) = .25 and P(A or B) = .75, then which of the following is correct?
a)
b)
c)
d)
P(A and B) = 0
P(A and B) = .25
P(A and B) = .50
P(A and B) = .75
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STAT 3090
Test #1 (Version B)
Spring 2016
11. The number of ounces in a Tall Mocha Latte at Starbucks is what type of data?
a)
b)
c)
d)
Quantitative, discrete
Quantitative, continuous
Qualitative, continuous
Qualitative, discrete
12. Your CUID is an example of what level of data?
a)
b)
c)
d)
Nominal
Ordinal
Interval
Ratio
Below is a stem and leaf plot where 1|5 = 1.5
0|2
0|5889
1|1
1|67899
2|223
13. The shape of the distribution is best described as
a) Approximately mound shaped
b) Bimodal
c) Uniform
d) Skewed right
14. Given two mutually exclusive events with P(A) = 0.6 and P(B) = 0.2, then P(A and B) is equal to:
a)
b)
c)
d)
0.0
0.8
0.12
0.68
15. The number of hours per week that a group of fitness fanatics exercise is determined for each fanatic in a sample. The
mean of the data is 32 hours and the median is 28.2 hours. Twenty-four of the fanatics in the sample exercised for 17
hours or less for the week. The 11th percentile of the data is 17 hours. Based on the following information, which of
the following do you know is true?
a)
b)
c)
d)
The 57th percentile is greater than 27 hours.
The 60th percentile is less than 32 hours
There are 200 fanatics in the sample
24 fanatics in the sample exercised between 17 hours and 28.2 hours.
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STAT 3090
Test #1 (Version B)
Spring 2016
16. The height of the students in one high school has an average of 69 inches and a standard deviation of 2 inches.
Assuming the data is bimodal, what minimum percentage of students have height between 63 inches and 75 inches?
a)
b)
c)
d)
68%
95%
88.89%
75%
17. While shopping in the mall, 200 people were stopped and asked if they would be willing to perform a taste test in
which they drink from two randomly placed, unmarked cups and asked which beverage they prefer. This is an
example of which of the following:
a)
b)
c)
d)
An observational study since the people were chosen while they were shopping
An observational study since the researcher simply observed which cup the person chose
An experiment because the sample was made up of volunteers
An experiment because the person tasting did not know which brand was in which cup
18. The U.S. Department of Housing and Urban Development (HUD) wants to describe the average price of a home in
the United States. Which measure would best describe the average housing price?
a)
b)
c)
d)
The mean
The Standard Deviation
The median
The mode
19. Which of the following is not an example of independent events?
a) Flipping a coin until you get a head
b) Drawing two cards from a deck of cards one at a time (without replacement) and getting cards of the same
suit each time
c) The battery in both your cell phone and your calculator are dead
d) You flip a coin and get a head and roll a die and get a 5
20. If constant is added to each of a set of numbers, then:
a)
b)
c)
d)
The mean and standard deviation will stay the same.
The mean and standard deviation will both increase.
The mean will increase but the standard deviation will stay the same.
The overall mean will stay the same, but the standard deviation will increase.
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STAT 3090
Test #1 (Version B)
Spring 2016
Part II: Free Response. Show all your work. Indicate clearly the methods you use, because you will be graded
on the correctness of your methods as well as on the accuracy and completeness of your results and
explanations. Answers with no justification will receive no credit.
Free Response: Total 40 points
1. Clemson University scores on the chemistry final exam are normally distributed with a mean of 76 and a
standard deviation of 12, while the scores on calculus are also normally distributed with a mean of 70 and a
standard deviation of 10. Ashley scored 90 on chemistry and 78 on calculus? Relative to the students in
each respective class, in which subject did she do better? Show all work and round your answer to two
decimals.
2. Mr. Zuro has recorded exam grades for 25 students in his class, but one of the grades is no longer readable.
If the mean score on the exam was 82 and mean of the 24 readable scores is 84, what is the value of the
unreadable score? Show all work.
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STAT 3090
Test #1 (Version B)
Spring 2016
Use the following information to answer questions 3 a and 3b..
A municipal worker’s union that represents sanitation workers in many small Midwestern cities studied the
contracts that were signed in previous years. The contracts were subdivided into those settled by arbitration
without a strike, and all those settled after a strike. For each of these contracts the five-year percentage wage
increase was determined. Summary figures follow.
Contract Type
Mean percentage wage increase per hour
Standard Deviation
Arbitration
9.42%
1.02%
Post-strike
8.40%
1.21%
3a. Using in the empirical rule what percentage of contracts that were settled by arbitration without strike
resulted in a wage increase between 8.40% and 12.48%? Show work or draw a sketch.
3b. According to Chebyshev’s Theorem, at least 75% of the contracts settled after a strike resulted in wage
increases between what percent? Show all work. No credit if no work shown. Show proper units.
[____________ ,_________________].
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STAT 3090
Test #1 (Version B)
Spring 2016
4. Given the following set of data from a sample of the number of tax forms completed by an accountant on five
different days:
30
23
14
18
20
The MEAN of the sample is 21. Calculate the Variance and Standard Deviation of the number of tax
forms completed. Show ALL work and clearly label the Variance and Standard Deviation.
Variance _______________
Standard Deviation _____________
Page 9 of 11
STAT 3090
Test #1 (Version B)
Spring 2016
The following 20 test scores were recorded for an economics final exam. Use these to answer Questions
5a, 5b and 5c.
41 42 44 50 56
60 64 69 71 78
80 81 87 90 90
94 96 100 100 100
5a) Compute the 5-number summary. Show all work for full credit. Round to one decimal if necessary.
5b) Compute the Upper and Lower Fences. Show all work for full credit. Round to one decimal.
5c) Are there any outliers? Justify your answer.
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STAT 3090
Test #1 (Version B)
Spring 2016
Use the following information to answer questions 6a and 6b.
Researchers asked 2160 randomly selected adults "When you see an ad emphasizing 'Made in America,'
are you More likely to buy it, Less likely to buy it, or Neither More nor Less likely to buy it? Results are
shown in the table below.
More Likely
Less Likely
Neither More nor Less Likely
TOTAL
18 – 34 yrs old
238
22
282
542
35 – 44 yrs old
329
6
201
536
45 – 54 yrs old
360
22
164
546
55 yrs or older
402
16
118
536
TOTAL
1329
66
765
2160
6a. Given that a randomly selected person is 35 - 54 years of age or older, what is the probability that he/she is
less likely to buy? Show all work and leave your answer in an unreduced fraction!
6b. Are the events 35 – 54 years of age and less likely to buy independent events? Justify your answer of
"independent" or "dependent" using probability rules. Answers with no work will receive NO credit.
7. Did you correctly fill in your scantron? (1 pt)
 Did you write your name, lecture section #, and lecture instructor at the top of the form?
 Did you fill in your CUID with the C bubbled as a 0?
 Did you bubble in your Test Version?
 Are your bubbles filled in dark enough so that the form can be machine read?
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