Question

uestion

A1A Tires claims that its tires last longer than tires manufactured by its main competitor, YYZ Tires. A consumer group studied the lifespans of tires manufactured by each manufacturer. The lifespans of a random sample of 10 tires from each manufacturer, in thousands of miles, are recorded.

Assume that the population standard deviation of the lifespan for tires manufactured by A1A Tires is 3 thousand miles, while the population standard deviation of the lifespan for tires manufactured by YYZ Tires is 5 thousand miles, and assume that the lifespans of both companies' tires are normally distributed. Let A1A Tires be the first sample, and let YYZ Tires be the second sample.

The consumer group conducts a two-mean hypothesis test at the 0.05 level of significance, to test if there is evidence that A1A Tires' claim is true.

(a) H0:μ1=μ2; Ha:μ1>μ2, which is a right-tailed test.

(b) z≈3.09 , p-value is approximately 0.001

(c) Which of the following are appropriate conclusions for this hypothesis test? Select all that apply.

Select all that apply:

• Reject H0.

• There is sufficient evidence at the 0.05 level of significance to conclude that the tires manufactured by A1A Tires do in fact last longer than those manufactured by YYZ Tires.

• Fail to reject H0.

• There is insufficient evidence at the 0.05 level of significance to conclude that the tires manufactured by A1A Tires do in fact last longer than those manufactured by YYZ Tires.

Answer 1