Question

A sample of 64 observations is selected from a normal population. The sample mean is 215, and the population standard deviation is 15. Conduct the following test of hypothesis using the 0.03 significance level: HO: u? 220 H1 : < 220 a. Is this a one-or two-tailed test? Two-tailed b. What is the decision rule? (Negative answer should be indicated by a minus sign. Round the final answer to 2 decimal places.) (Click to select) v Ho when z< D . c. The value of the test statistic is (Negative answer should be indicated by a minus sign. Round the final answer to 2 decimal places.) -2.67 d. What is your decision regarding He? Reject Ho e. What is the p-value? (Round the final answer to 4 decimal places.)

Answer 1

Answer

(A) it is a one tailed hypothesis test because the alternate hypothesis is showing a less than symbol

(B) Significance level is 0.03

z critical = NORMSINV(alpha)

= NORMSINV(0.03)

= -1.88

Reject Ho if z < -1.88

(C) z statistic = -2.67 (already calculated)

(D) it is clear that z value is less than -1.88, so we will reject null hypothesis Ho and result is significant

(E) p value = NORMSDIST(z)

set z = -2.67

we get

p value = NORMSDIST(-2.67)

= 0.0038