Question 15 pts

The symbol for the power of a statistical test is

Group of answer choices

1 -

1 -

Flag question: Question 2Question 25 pts

The marketing manager for an automobile manufacturer is interested in determining the proportion of new compact-car owners who would have purchased a GPS navigation system if it had been available for an additional cost of $300. The manager believes from previous information that the proportion is 0.30. Suppose that a survey of 200 new compact-car owners is selected and 79 indicate that they would have purchased the GPS navigation system. If you were to conduct a test to determine whether there is evidence that the proportion is different from 0.30, which test would you use?

Group of answer choices

Z-test of a population mean

Z-test of a population proportion

t-test of a population mean

t-test of a population proportion

Flag question: Question 3Question 35 pts

A sample is used to obtain a 95% confidence interval for the mean of a population. The confidence interval goes from 15 to 19. If the same sample had been used to test the null hypothesis that the mean of the population is equal to 18 vs. the alternative hypothesis that the mean of the population differs from 18, the null hypothesis could be rejected at a level of significance of 0.05.

Group of answer choices

True

False

Flag question: Question 4Question 45 pts

The quality control engineer for a furniture manufacturer is interested in the mean amount of force necessary to produce cracks in stressed oak furniture. She performs a two-tail test of the null hypothesis that the mean for the stressed oak furniture is 650. The calculated value of the Z-test statistic is a positive number that leads to a p-value of 0.080 for the test. If the test is performed with a level of significance of 0.10, the null hypothesis would be rejected.

Group of answer choices

True

False

Flag question: Question 5Question 55 pts

A drug company is considering marketing a new local anesthetic. The effective time of the anesthetic the drug company is currently producing has a normal distribution with a mean of 7.4 minutes with a standard deviation of 1.2 minutes. The chemistry of the new anesthetic is such that the effective time should be normally distributed with the same standard deviation, but the mean effective time may be lower. If it is lower, the drug company will market the new anesthetic; otherwise, they will continue to produce the older one. A sample size of 36 results in a sample mean of 7.1. A hypothesis test will be done to help make the decision. If the level of significance had been chosen as 0.05, the null hypothesis would be rejected.

Group of answer choices

True

False

Flag question: Question 6Question 65 pts

Suppose, in testing a hypothesis about a mean, the p-value is computed to be 0.034. The null hypothesis should be rejected if the chosen level of significance is 0.01.

Group of answer choices

True

False

Flag question: Question 7Question 75 pts

How many tissues should the Kimberly-Clark Corporation package of Kleenex contain? Researchers determined that 60 tissues is the mean number of tissues used during a cold. Suppose a random sample of 100 Kleenex users yielded the following data on the number of tissues used during a cold:x = 52 and S = 22. Give the null and alternative hypotheses to determine if the number of tissues used during a cold is less than 60.

Group of answer choices

H0:60andH1:>60

H0:60andH1:<60

H0:X60andH1:X<60

H0:X=52andH1:X52

Flag question: Question 8Question 85 pts

If, as a result of a hypothesis test, you reject the null hypothesis when it is false, then you have committed

Group of answer choices

A Type II error

A Type I error

No error

An acceptance error

Flag question: Question 9Question 95 pts

For a given level of significance (), if the sample size n is increased, the probability of a Type II error ()

Group of answer choices

Will decrease

Will increase

Will remain the same

Cannot be determined

Flag question: Question 10Question 105 pts

Many companies use well-known celebrities as spokespersons in their TV advertisements. A study was conducted to determine whether brand awareness of female TV viewers and the gender of the spokesperson are independent. Each in a sample of 300 female TV viewers was asked to identify a product advertised by a celebrity spokesperson. The gender of the spokesperson and whether or not the viewer could identify the product was recorded. The numbers in each category are given below.

	Male Celebrity	Female Celebrity
Identified Product	41	61
Could Not Identify	109	89

At 5% level of significance, the critical value of the test statistic is

Group of answer choices

3.8415

5.9914

9.4877

13.2767

Flag question: Question 11Question 115 pts

Many companies use well-known celebrities as spokespersons in their TV advertisements. A study was conducted to determine whether brand awareness of female TV viewers and the gender of the spokesperson are independent. Each in a sample of 300 female TV viewers was asked to identify a product advertised by a celebrity spokesperson. The gender of the spokesperson and whether or not the viewer could identify the product was recorded. The numbers in each category are given below.

	Male Celebrity	Female Celebrity
Identified Product	41	61
Could Not Identify	109	89

At 5% level of significance, the conclusion is that

Group of answer choices

Brand awareness of female TV viewers and the gender of the spokesperson are independent

Brand awareness of female TV viewers and the gender of the spokesperson are not independent

Brand awareness of female TV viewers and the gender of the spokesperson are related

Both (b) and (c)

Flag question: Question 12Question 125 pts

If we use thex2method of analysis to test for the differences among four proportions, the degrees of freedom are equal to

Group of answer choices

3

4

5

1

Flag question: Question 13Question 135 pts

According to an article in Marketing News, fewer checks are being written at the grocery store checkout than in the past. To determine whether there is a difference in the proportion of shoppers who pay by check among three consecutive years at a 0.05 level of significance, the results of a survey of 500 shoppers in three consecutive years are obtained and presented below.

	Year
Check Written	Year 1	Year 2	Year 3
Yes	225	175	125
No	275	325	375

What is the form of the null hypothesis?

Group of answer choices

H0:1=2=3

H0:1=23

H0:12=3

H0:123

Flag question: Question 14Question 145 pts

A computer used by a 24-hour banking service is supposed to randomly assign each transaction to one of five memory locations. A check at the end of a day's transactions gave the counts shown in the table to each of the five memory locations, along with the number of reported errors.

Memory Location	1	2	3	4	5
Number of Transactions	82	100	74	92	102
Number of Reported Errors	11	12	6	9	10

The bank manager wanted to test whether the proportion of errors in transactions assigned to each of the five memory locations differ. The calculated value of the test statistic is

Group of answer choices

-0.1777

-0.0185

1.4999

1.5190

Flag question: Question 15Question 155 pts

When using the x2 tests for independence, you should be aware that expected frequencies that are too small will lead to a large Type I error.

Group of answer choices

True

False

Flag question: Question 16Question 165 pts

The Y-intercept (b0) represents the

Group of answer choices

Estimated average Y when X = 0

Change in estimated average Y per unit change in X

Predicted value of Y

Variation around the sample regression line

Flag question: Question 17Question 175 pts

The strength of the linear relationship between two numerical variables may be measured by the

Group of answer choices

Scatter plot

Coefficient of correlation

Slope

Y-intercept

Flag question: Question 18Question 185 pts

A computer software developer would like to use the number of downloads (in thousands) for the trial version of his new shareware to predict the amount of revenue (in thousands of dollars) he can make on the full version of the new shareware. Following is the output from a simple linear regression along with the residual plot and normal probability plot obtained from a data set of 30 different sharewares that he has developed.

Regression Statistics
Multiple R	0.8691
R Square	0.7554
Adjusted R Square	0.7467
Standard Error	44.4765
Observations	30.0000

ANOVA
	df	SS	MS	F	SignificanceF
Regression	1	171062.9193	171062.9193	86.4759	0.0000
Residual	28	55388.4309	1978.1582
Total	29	226451.3503

	Coefficients	Standard Error	t Stat	P-vlaue	Lower 95%	Upper 95%
Intercept	-95.0614	26.9183	-3.5315	0.0015	-150.2009	-39.9218
Download	3.7297	0.4011	9.2992	0.0000	2.9082	4.5513

There is sufficient evidence that revenue and the number of downloads are linearly related at a 5% level of significance.

Group of answer choices

True

False

Flag question: Question 19Question 195 pts

The following Excel tables are obtained when the score received on an exam (measured in percentage points) (Y) is regressed on percentage attendance (X) for 22 students in a Statistics for Business and Economics course.

Regression Statistics
Multiple R	0.142620229
R Square	0.02034053
Standard Error	20.25979924
Observations	22

	Coefficients	Standard Error	T Stat	P-value
Intercept	39.3902730	37.24347659	1.057642216	0.30282662
Attendance	0.34058357	0.52852452	0.644404489	0.52663568

Which of the following statements is true?

Group of answer choices

14.26% of the total variability in the score received can be explained by percentage attendance

14.2% of the total variability in percentage attendance can be explained by the score received

2% of the total variability in the score received can be explained by percentage attendance

2% of the total variability in percentage attendance can be explained by the score received

Flag question: Question 20Question 205 pts

The coefficient of determination (r2) tells you

Group of answer choices

That the coefficient of correlation (r) is larger than 1

Whether r has any significance

That you should not partition the total variation

The proportion of total variation that is explained