An online retailer ships products from overseas with an advertised delivery date within 10 days. To test whether or not deliveries are made within the advertised time, a random sample of 10 orders is selected from a normal population. The sample mean delivery time is 12 days, and the standard deviation is 3 days. Given the following hypotheses:
H₀: μ ≤ 10
H₁: μ > 10
Using the 0.05 significance level:
a. State the decision rule.
b. Compute the value of the test statistic.
c. What is your decision regarding the null hypothesis?