Steve cutter sells big blade lawn mowers in his hardware store, and he is interested in comparing the reliability of the mowers he sells with the reliability of Big blade mowers sold nationwide. Steve knows that only 15 percent of all Big Blade mowers sold nationwide require repairs during the first year of ownership. A sample of 120 of Steve�fs customers revealed that exactly 22 of them required mower repairs in the first year of ownership. At the .02 level of significance, is there evidence that Steve�fs big blade movers differ in reliability from those sold nationwide?

1. The appropriate null hypothesis is:

a. ƒÊ = .15

b. ƒÎ = .15

c. ƒÊ �‚.15

d. ƒÎ �‚.15

e. p = .15

2. Assume the same facts as above, except that is is known that the alternative has a �‚ in it (that may or may not be the case above.) the critical value would then be +-:

a. 1.96

b. 2.05

c. 2.33

d. 2.58

e. 3.499 Letter corresponding to the Test Statistic to be used is ______ (Use Letters A - K)

A a

To determine if Steve's big blade mowers differ in reliability from those sold nationwide, we can use a hypothesis test.

1. The appropriate null hypothesis is:
e. p = .15

In this case, we are comparing the reliability of Steve's mowers to the nationwide reliability, so we are assuming that the proportion of Steve's mowers requiring repairs (p) is equal to the proportion nationwide, which is 15%.

2. To find the critical value, we need to determine the test statistic. Since the sample size is large (n > 30) and we are dealing with proportions, we can use the normal distribution and the Z-test statistic.

The critical value at the 0.02 level of significance (2-tailed test) is:

c. 2.33

This value corresponds to an alpha of 0.01 for each tail of the distribution.

The letter corresponding to the test statistic to be used is not provided in the question. However, if we assume it is a Z-test, then the letter corresponding to the test statistic would be:

Letter F

(As a side note, the specific letter corresponding to the test statistic may vary depending on the textbook or reference materials used, as different sources may use different letters for referencing statistics.)