. A manufacturer of car batteries claims that the life of his batteries is approximately normally...

. A manufacturer of car batteries claims that the life of his batteries is approximately normally distributed with a standard deviation of more than 0.9 years. They wish to test this hypothesis using a random sample of 10 of these batteries and a level of significance of 0.05.

(a) State the null and alternative hypothesis, the test statistic, and the critical region.

(b) Suppose the sample standard deviation is 1.2 years. State and interpret the conclusion of the test.

(c) Construct a relevant confidence interval.

(d) Use a P-value to determine the conclusion resulting from the test.

Expert Solution

orchestra answered 2 years ago

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