Your organization has a goal of 15 days for the average proc

Your organization has a goal of 15 days for the average processing of a purchase request (PR) from notification to final approval. They are only concerned if it takes longer than 15 days. A sample of 25 PRs produced a mean of 15.5 days and a standard deviation of 1.5 days. Test at the 10% level of significance whether they are meeting their goal. Select the correct answer out of each pair of choices. (Carry intermediate calculations to three decimal places.) (select all that apply)

A) 1. tp is 1.711 or 2 . tp is 1.318

B) 1. tc is 1.667 or 2. tc is 5.000

C) We would reject the null hypothesis

     We would fail to reject the null hypothesis

D) We would conclude that the organization IS meeting their goal

     We would conclude that the organization IS NOT meeting their goal

Solution

The test hypothesis:

Ho: mu=15 (i.e. null hypothesis)

Ha: mu>15 (i.e. alternative hypothesis)

The test statistic is

t=(xbar-mu)/(s/vn)

=(15.5-15)/(1.5/sqrt(25))

=1.67

Answer: B) 1. tc is 1.667 or 2. tc is 5.000

We would reject the null hypothesis

We would conclude that the organization IS meeting their goal