Test Bank (Excel)

Test Bank (Excel)

1.

A company has recorded data on the weekly sales for its product (y) and the unit price of the competitor’s product (x). The data resulting from a random sample of 7 weeks follows. Use Excel’s Regression Tool to answer the following questions.

Week / Price / Sales
1 / .33 / 20
2 / .25 / 14
3 / .44 / 22
4 / .40 / 21
5 / .35 / 16
6 / .39 / 19
7 / .29 / 15

a. What is the estimated regression equation?

b.Perform a t-test and determine whether or not x and y are related. Use  = 0.05.

c.Perform an F-test and determine whether or not x and y are related. Use  = 0.05.

d. Find and interpret the coefficient of determination.

2.

One thousand managers with degrees in business administration indicated their fields of concentration as shown below.

Major / Top Management / Middle Management / TOTAL
Management / 300 / 200 / 500
Marketing / 200 / 0 / 200
Accounting / 100 / 200 / 300
TOTAL / 600 / 400 / 1000

Test at  = .01 to determine if the position in management is independent of the major of concentration.

Members of a focus group stated their preferences between three possible slogans. The results follow. Use Excel to test at  = .05 to determine any difference in preference among the three slogans.

Slogan Preferences
A / A / C / C / B
C / B / B / A / A
B / C / A / B / C
C / C / C / B / B
C / B / C / C / A
A / A / C / A / B

4.

Below you are given ages that were obtained by taking a random sample of 9 undergraduate

students.

192223192122192321

Use Excel to determine an interval estimate for the mean of the population at a 99% confidence level. Interpret your results.

5.

Guitars R. US has three stores located in three different areas. Random samples of the sales

of the three stores (in $1000) are shown below.

Store 1Store 2Store 3

808579

758685

768188

8980

At a .05 level of significance, use Excel to test to see if there is a significant difference in the average sales of the three stores.

6.

A group of young businesswomen wish to open a high fashion boutique in a vacant

store, but only if the average income of households in the area is more than $45,000.

A random sample of 9 households showed the following results.

$48,000$44,000$46,000$45,000

$43,000$47,000$46,000$42,000 $44,000

Use the statistical techniques in Excel to advise the group on whether or not they should locate the boutique in this store (i.e., test ) . Use a .05 level of significance.

7.

A manufacturer claims that at least 40% of its customers use coupons (). A

study of 25 customers is undertaken to test that claim. The results of the study follow.

yes / no / no / yes / yes
no / yes / no / no / yes
no / no / no / no / yes
no / no / no / no / yes
no / no / yes / no / yes

At a .05 level of significance, use Excel to test the manufacturer’s claim.

8.

The sponsors of televisions shows targeted at the market of 5 – 8 year olds want to test the

hypothesis that children watch television at most 20 hours per week (). A

market research firm conducted a random sample of 30 children in this age group. The

resulting data follows:

19.5 / 29.7 / 17.5 / 10.4 / 19.4 / 18.4
14.6 / 10.1 / 12.5 / 18.2 / 19.1 / 30.9
22.2 / 19.8 / 11.8 / 19.0 / 27.7 / 25.3
27.4 / 26.5 / 16.1 / 21.7 / 20.6 / 32.9
27.0 / 15.6 / 17.1 / 19.2 / 20.1 / 17.7

At a .10 level of significance, use Excel to test the sponsors’ hypothesis.

A manufacturing company wants to estimate the difference in the proportion of defective parts between two machines. Independent random samples of parts are taken from both machines. The results follow. Use Excel to estimate the difference in the proportion of defective parts between two machines with a 99% level of confidence.

Machine 1 /

Machine 2

yes / Yes / no / no / no / no
no / Yes / no / no / yes / no
no / No / no / no / no / no
no / Yes / no / no / no / no
no / No / no / yes / no / no
no / No / no / no / yes / no
no / No / no / yes / no / no
no / Yes / no / no / no / no
no / No / no / no / yes / no
no / No / no / yes / no / no

10.

Independent samples of commuters are taken from two cities. The following data represents

the time (in minutes) to drive to work. Use Excel to determine whether the average commuting times are significantly different between the two cities. Use  = .05.

City A /

City B

15.25 / 40.25 / 12.75 / 48.75
25.50 / 50.00 / 12.50 / 12.25
18.75 / 45.00 / 15.50 / 10.00
60.25 / 16.75 / 22.75 / 42.00
10.50 / 18.75 / 38.75 / 42.50
10.50 / 28.50 / 45.00 / 12.25
35.75 / 30.00

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