The mean gross annual incomes of certified tack welders are normally distributed with the mean of $50,000 and a standard deviation of $4,000. The ship building association wishes to find out whether their tack welders earn more or less than $50,000 annually. The alternate hypothesis is that the mean is not $50,000.
If the level of significance is 0.10, what is the decision rule?
A) Do not reject the null hypothesis if computed z lies between -1.65 and +1.65; otherwise, reject it
B) Do not reject the null hypothesis if computed z is greater than 1.65; otherwise, reject it
C) Do not reject the null hypothesis if computed z lies between -1.96 and +1.96; otherwise, reject it
D) Reject the null hypothesis if computed z is below -1.96; otherwise, reject it
E) None of these statements are true

Question

Quizplus · Accepted Answer

The decision rule for a two-tailed test with a significance level of 0.10 is to reject the null hypothesis if the computed z-score is less than -1.65 or greater than 1.65.

The Mean Gross Annual Incomes of Certified Tack Welders Are