An analyst claims that the mean annual salary for advertising account executives in Denver, Colorado, is more than the national mean, $67,800. The annual salaries (in dollars) for a random sample of 21 advertising account executives in Denver are listed. Assume the population is normally distributed and the population standard deviation is $7800. At α = 0.09, is there enough evidence to support the analyst’s claim?

(a) Identify the claim and state H₀ and H_a.

(b) Find the standardized test statistic z. If convenient, use technology.

(c) Find the P-value. If convenient, use technology.

(d) Decide whether to reject or fail to reject the null hypothesis.

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

Transcribed Image Text:

57,860 66,863 91,982 66,979 66,940 82,976 67,073 72,006 73,496 72,972 66,169 65,983 55,646 62.758 58,012 63,756 75,536 60.403 70445 61,507 66,555