Question

Help Save & Exit Check my A consumer advocate researches the length of life between two brands of refrigerators, Brand A and Brand B. He collects data (measured in years) on the longevity of 40 refrigerators for Brand A and repeats the sampling for Brand B. These data are measured in years. (You may find it useful to reference the appropriate table: z table or table) 10 points Brand A Brand B Brand A Brand B eBook **************** 3322282292393282939 Click here for the Excel Data File une that mi is the mean longevity for Brand A and is the mean longevity for Brand B. a. Select the competing hypotheses to test whether the average length of life differs between the two brands. NOT - W2 - 0; WA M1 - H2 Hot - 22 01 HAM - N20 < Prev 2 of 5 Next >

Answer 1

Answer:

a).

Ho: µ1 = µ2   H1: µ1 ≠ µ2

b1).

population standard deviation known. z test used.

(C1-C2) - 11

17.575-18.525) 42 5

= -1.88

Test statistic = -1.88

b2).

P value:

0.05<p value <0.10

c).

Do not reject Ho, there is no evidence that the average life differs between the brands

Descriptive statistics
	A	B
count	40	40
mean	17.5750	18.5250

Z Test for Differences in Two Means
Data
Hypothesized Difference	0
Level of Significance	0.05
Population 1 Sample
Sample Size	40
Sample Mean	17.575
Population Standard Deviation	2.213594362
Population 2 Sample
Sample Size	40
Sample Mean	18.525
Population Standard Deviation	2.302172887
Intermediate Calculations
Difference in Sample Means	-0.95
Standard Error of the Difference in Means	0.5050
Z Test Statistic	-1.8813
Two-Tail Test
Lower Critical Value	-1.9600
Upper Critical Value	1.9600
p-Value	0.0599
Do not reject the null hypothesis