Question

You want to buy a microwave oven and will choose Model A if its repair costs are lower than Model​ B's. You research the repair costs of 48 Model A ovens and 55 Model B ovens. The results of your research are shown in the figure to the right. x overbar 1= $78 s1= $11.50 x overbar 2= $70 s2= $30 At alphaαequals=0.010.01​, would you buy Model​ A? Assume the samples are randomly selected and that the samples are independent. Complete parts​(a)-(e).

What is the​ claim?

A. Model​ A's repair costs are lower than Model​ B's

B. Model​ A's repair costs are different than Model​ B's.

C. Model​ A's repair costs are the same as Model​ B's.

D. Model​ A's repair costs are greater than Model​ B's.

What are

Upper H 0H0

and

Upper H Subscript aHa​?

A.Upper H0​: mu 1μ1greater than or equals≥mu 2μ2

Upper Ha​:mu 1μ less than<mu 2μ2

B. Upper H 0H0​:

mu 1μ1equals=mu 2μ2

Upper H Subscript aHa​:

mu 1μ1not equals≠mu 2μ2

C. Upper H 0H0​:

mu 1μ1less than<mu 2μ2

Upper H Subscript aHa​:

mu 1μ1greater than or equals≥mu 2

(b) Find the critical​ value(s) and identify the rejection​ region(s).

The critical​ value(s) is/are

nothing.

​(Round to two decimal places as needed. Use a comma to separate answers as​needed.)

A. zgreater than>2.575

B. zless than<minus−​2.33,

zgreater than>minus−2.33

C. zless than<minus−2.33

D. zless than<3.32

E. zless than<​3.32,

zgreater than>3.32

F. zgreater than>minus−3.08

G. zless than<​2.575,

zgreater than>2.575

H. zless than<minus−​3.08,

zgreater than>minus−3.08

(c) Find the standardized test statistic z.

z=_____​(Round to two decimal places as​ needed.)\

(d) Decide whether to reject or fail to reject the null hypothesis. Choose the correct answer below.

A.Reject H0 The standardized test statistic is in the rejection region.

B. Reject H0 the standardized test statistic is not in the rejection region.

C. Fail to reject H0 The standardized test statistic is not in the rejection region.

D.Fail to reject H0 the standardized test statistic is in the rejection region.

​(e) Interpret the decision in the context of the original claim.

At the ____​% significance​ level, there is sufficient/insufficient to reject/support

the claim that the repair costs for Model A are lower than/different than/equal to/greater than

for Model B.

Answer 1