Practice Exam Final

8/17/2019 Practice Exam Final

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COURSE: QUMT 3343 Name: _______________________Final Exam: Practice A Last, First (printed)

Instructions:

Please put your name, test version (i.e. 1- A or B), date, class section

number in subject box on your scantron.

You have 100 minutes to complete this exam. You may use yourmemory enhancement documents and calculator. Please show all yourwork on the exam and mark all answers on the exam and scantron.No computers or cell phones.

This test consists of 30 questions. Each question is worth 3.33

points for a possible 100 total points.

Good luck!


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QUMT 3343 Final Exam Study Guide

o Four levels of measuremento Sample vs. population; statistic vs. parametero

Stem and leaf interpretationo Stem and leaf; Frequency distribution table; how to converto Meano Modeo Mediano Standard Deviation of a sampleo Marginal probo Union Probo Conditional Probo General Law of Additiono Properties of normal curveo

Prob of standard Normal Distribution (between, greater, less)o

Central limit theoremo Confidence intervals when σ is known o Confidence intervals and the Empirical rule (from chapter 4)o Confidence intervals when σ is unknown o Hypothesis tests of single populations when σ is known

o Hypothesis tests of single populations when σ is unknown

o Hypothesis tests of two populations

o Hypothesis test statistic’s o Hypothesis determine critical valueso Hypothesis compute p-value of a Z-test

o

Interpret p-value’s by classic rules and rule-of-thumb (Ch 10 not covered verywell)

Classical rule: if p-value < α reject H0

Rule of thumb:

If p-value < .05 reject H0

If p-value > 0.1 FTR H0

If 0.05


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1. The license plate on a car. It is __________ data and is _________________ data. (levels ofdata in chapter1.)

A. Qualitative, RatioB. Qualitative, Nominal*

C.

Qualitative, IntervalD. Qualitative, Ordinal

2.

If the average age of UNT students in the Fall of 2006 is estimated from the ages of 500 students

selected at random across campus; this situation would be classified as a ---_______________ that

produces a ___________.

A.

sample & parameterB.

census & parameterC.

census & statisticD.

sample & statistic*

Questions #3 - #4 refers to the following stem-and-leaf diagram which displays local mortgage rates

(annual percentages) for a sample of banks in North Texas. (charts and graphs in chapter2)

Stem Leaf (unit = .1)

4 0 1 5 7 85 2 3 6 6 8 8 86 4 5 6 8 98 6 6 7 8 9 9 9 9

3. What percentage of the interest rates are not less than 5.20%?A. 79.4%B. 20.0%C. 21.6%D. 80.0%*

4. What is the highest mortgage rate in the data set ?A. 8.9% *B. 4.9%C. 2.8%

D.

5.8%

5. What is the cumulative frequency for mortgage rates under 6%?

A. 89%B. 48%C. 12*D. 17


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Use the following sample values to answer questions #6 through #9: (percentile, quartile, and other

measures in chapter 3)

5, 6, 4, 5, 11

6.

What is the sample mean?

A. 5.00B. 6.00C. 6.20*D. 6.50

7. This data has _________________.

A. No ModeB. One mode*

C. Two modesD. Three modes

8. What is the median?

A. 5.0*B. 6.0C. 7.0D. 6.5

9.

Compute the sample standard deviation

A. 7.70B. 2.77*C. 3.42D. 6.50

A university is interested in determining whether an association exists between smoking and gender.A random sample of 72 students results in the following two-way table of counts:

Smoking

Gender Smoker (S ) Non-Smoker ( NS )Female (F ) 3 31

Male ( M ) 6 32

10.

______ P (S)What is the probability that a randomly selected student is a smoker?

(A) 9/63 (B) 3/6 (C) 3/9 (D) 9/72*


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11.

______ P(S|M)?

What is the probability that a student is a smoker given that the student is male?

(A) 6/9 (B) 6/38* (C) 6/32 (D) 6/72

12.

______ P(S ∪

M)What is the probability that a randomly selected student is a smoker or male?

(A) 41/72 * (B) 47/72 (C) 6/38 (D) 6/9

For Questions #13 - #15: Denton has recently installed computer controlled cameras toissue traffic tickets. The contingency table below describes how 550 people react toreceiving these tickets:

Traffic Violation Pays the Ticket Fights the TicketRun Red Light 150 110Speeding 160 130

13.

What is the probability of selecting a person at random who Pays the Ticket?(A) 0.564 *(B) 0.273(C) 0.472(D) 0.436

14. What is the probability of selecting a person, at random, that receives a SpeedingTicket or Fights the Ticket?(A) 0.727 *

(B)

0.750(C) 0.236(D) 0.964

15. Given that a person Fights the Ticket, what is the probability that the person was Speeding?(A) 0.964(B) 0.542*(C)

0.236(D) 0.527

16. The area to the left of the mean in any normal distribution is equal to _______.a) the mean b) 1c) the varianced) 0.5*e) -0.5

17. Let z be a normal random variable with mean 0 and standard deviation 1. What is P( z < 1.3)?


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a) 0.4032 b) 0.9032*c) 0.0968d) 0.3485e) 0. 5485

18.

The area under the normal curve bounded by Z = 1.2 to 2.2 is approximately .

(A)

.3849(B)

.8710(C)

.1012*(D)

.1650(E)

.4861

19.

Suppose a population has a mean of 90 and a standard deviation of 28. If a random sample ofsize 49 is drawn from the population, the probability of drawing a sample with a mean ofmore than 95 is _______.a) 0.1056* b) 0.3944c) 0.4286d) 0.8944e) 1.0000

20. Suppose a population has a mean of 90 and a standard deviation of 28. If a random sample ofsize 49 is drawn from the population, the probability of drawing a sample with a mean between 80 and 100 is _______.a) 0.9876* b) 0.0124c) 0.4938d) 0.0062e) 1.0000

21. Suppose a population has a mean of 400 and a standard deviation of 24. If a random sampleof size 144 is drawn from the population, the probability of drawing a sample with a mean ofmore than 404.5 is _______.a) 0.0139

b) 0.4861c) 0.4878d) 0.0122*e) 0.5000


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22. The expected (mean) life of a particular type of light bulb is 1,000 hours with a standarddeviation of 50 hours. The life of this bulb is normally distributed. What is the probabilitythat a randomly selected bulb would last fewer than 940 hours?a) 0.3849 b) 0.8849

c) 0.1151*d) 0.6151e) 0.6563

23. The table t value associated with the upper 5% of the t distribution and 12 degrees offreedom is _______.a) 2.179 b) 1.782*c) 1.356d) 3.055

24. The dean of a business school claims that the average starting salary of its graduates is morethan 60 (in $000’s). It is known that the population standard deviation is 10 (in $000’s).Sample data on the starting salaries of 64 randomly selected recent graduates yielded a meanof 62 (in $000s). Which of the following sets of hypotheses is correct?a) H0: μ = 60 and Ha: μ ≠ 60 b) H0: μ = 60 and Ha: μ < 60c) H0: μ = 60 and Ha: μ > 60*d) H0: μ > 60 and Ha: μ < 60e) H0: μ < 60 and Ha: μ > 60

25. The dean of a business school claims that the average starting salary of its graduates is morethan 60 (in $000’s). It is known that the population standard deviation is 10 (in $000’s).Sample data on the starting salaries of 64 randomly selected recent graduates yielded a meanof 62 (in $000s). What is the value of the sample test statistic?a) 2.00 b) 1.80c) 1. 85d) 1.65e) 1.60 *

26. The dean of a business school claims that the average starting salary of its graduates is morethan 60 (in $000’s). It is known that the population standard deviation is 10 (in $000’s).Sample data on the starting salaries of 64 randomly selected recent graduates yielded a meanof 62 (in $000s). What is the critical value for the rejection region if the level of significanceis 5%?a) 2.00


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b) 1.80c) 1. 85d) 1.65*e) 1.60

27. The dean of a business school claims that the average starting salary of its graduates is morethan 60 (in $000’s). It is known that the population standard deviation is 10 (in $000’s).Sample data on the starting salaries of 64 randomly selected recent graduates yielded a meanof 62 (in $000s). What is the p-value for the hypothesis test to check out the dean’s claim?

a) 1.60 b) 1.65c) 0.4452d) 0.05e) 0.0548*

28. Consider the ANOVA table shown here for a one-way analysis of variance for anexperimental design in which there are four treatment levels.

Source Df SS MS F

Between 485.50

Error 715.50

Total 29

The F test statistic is __________.

5.88 *

29. The degrees of freedom for “Between” and for “Error” are ___________. a) 4 and 29 b) 3 and 26 *c) 3 and 29d) 4 and 30e) not determinable from the given information


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Please answer questions #26 – #30 based on the following information.

Louis Katz, a cost accountant at Papalote Plastics, Inc. (PPI), is analyzing the manufacturingcosts of a molded plastic telephone handset produced by PPI. Louis's independent variable is production lot size (in 1,000's of units), and his dependent variable is the total cost of the lot (in

$100's). Regression analysis of the data yielded the following tables.Coefficients Standard Error t Statistic p-value

Intercept 3.996 1.161268 3.441065 0.004885

x 0.358 0.102397 3.496205 0.004413

Source df SS MS F Se = 0.898

Regression 1 9.858769 9.858769 12.22345 r 2 = 0.526341

Residual 11 8.872 0.806545

Total 12 18.73077

30.

Louis's regression model is ________________. y = 3.996 + 0.358 x

31. For a lot size of 10,000 handsets, Louis' model predicts total cost will be _____.$757.60

32. p-value of the F-test is __________________.0.004413

33.

How to interpret R-square__________________.89.8% of the variation of cost could be explained by the lot size/regression model.

34.

If the actual cost is $800 when the lot size is 10,000 handsets, how much is the residual?$43.40


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The U.S. Bureau of Labor Statistics produced consumer price indexes for several differentcategories. Shown here are the percent changes in consumer price indexes over a period of 20year for food, shelter, apparel, and fuel oil. Also displayed are the percentage changes inconsumer prices indexes for all commodities. You did the multiple regression analysis to developa model that attempts to predict all commodities by the other four variables and the results are

displayed below.

Food Shelter Apparel Fuel Oil

All

Commodities

1 2 1.6 3.7 0.9

1.3 0.8 0.9 2.7 0.6

0.7 1.6 0.4 2.6 0.9

1.6 1.2 1.3 2.6 0.9

1.3 1.5 0.9 2.1 1.2

2.2 1.9 1.1 2.4 1.1

5 3 2.5 4.4 2.6

0.9 3.6 4.1 7.2 1.9

…… SUMMARY

OUTPUT

Regression Statistics

Multiple R 0.9814

R Square 0.9631

Adjusted R Square 0.9533

Standard Error 0.7472

Observations 20

ANOVA

df SS MS F

Significance

F

Regression 4 218.795 54.699 97.977 1.46055E-10

Residual 15 8.374 0.558

Total 19 227.170

Coefficients

Standard

Error t Stat P-value Lower 95%

Upper

95%Intercept -1.0590 0.3899 -2.7161 0.0159 -1.8901 -0.2280

Food 0.4753 0.0629 7.5594 0.0000 0.3413 0.6093

Shelter 0.2495 0.1005 2.4816 0.0254 0.0352 0.4638

Apparel -0.0084 0.1626 -0.0515 0.9596 -0.3550 0.3382

Fuel Oil 0.2721 0.1154 2.3575 0.0324 0.0261 0.5181


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35. Which set of independent variables are found to be not significant predictors of allcommodities index at the 0.05 level of significance?

a. Food b. Shelter

c.

Apparel *d. Fuel oile. None of them

36. What is the calculated value of the test statistic for apparel index as a predictor of allcommodities?

-0.0515

37. The calculated value of the test statistic to test the complete regression model is _____

97.977

38. What is the value of the correlation coefficient ?

0.9631

39. Overall, is this model significant at the 0.05 level of significance?

Yes.

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