Please answer this question

Question

The depot is using a standard of 650 hours for a particular modification effort. You are to review the standard and determine whether it should be revised. After sampling 20 of these modifications you calculate a mean of 665 hours and a standard deviation of 45 hours. We are concerned that the hours might be higher or lower than the 650 hour standard. Test the standard at the .05 level of significance. Select the correct answer out of each pair of choices. (Carry intermediate calculations to three decimal places.)

 
 
    The tp is 2.093

    The tp is 1.729


    The tc is 1.491

    The tc is 2.981


    We would fail to reject the null hypothesis

    We would reject the null hypothesis


    We would recommend using the existing standard.

    We would recommend revising the standard.

Answer 1

What would you say are the null and alternate hypotheses for this question ?