Question: Direct Mailing Company sells computers & computer parts by mail. The company claims that at least 90% of all orders are mailed within 72 hours after they are received. The quality control department at the company often takes samples to check if this claim is valid. A recently taken sample of 150 orders showed that 129 of them were mailed within 72 hours. Do you think the company's claim is true? Use a=0.1 significance level.

Step [A] State the null & alternative hypotheses.
Step [B] Make the appropriate test statistics & the rejection of your test.
Step [C] Calculate the value of the test statistic.
Step [D] Make a decision
Step [E] Find the p-value for the test of part a. What is your conclusion if α = 0.1?