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please answer d,e and f. (not a,b and c) 1. A company is deciding whether to ren

ID: 3131154 • Letter: P

Question

please answer d,e and f. (not a,b and c)

1. A company is deciding whether to renew its ad buy with a local TV station. It will renew the ad if a 2-sided hypothesis test at the 10% level concludes that more than 17.25% of the local residents remember the ad. They decide to test this by contacting 500 randomly selected local residents. Ninety-nine (99) of the 500 remember the ad a. Conduct the requested hypothesis test based on this sample using both the exact method, then the normal approximation. (Use Minitab) Report your conclusions. stated in terms of the sampling scenarid The station advocates that the decision be made based on a 1-sided hypothesis test at the 10% level using this sample. Why? (Hint: If you conduct the appropriate 1-sided test based on this sample using the normal approximation to the binomial, what will the p-value be? Confirm your answer with Minitab by conducting this 1-sided test.) If you conduct the 1-sided test based on this sample using the exact method, will the p-value be exactly one-half of the 2-sided exact method p-value? Why or why not? b. c.

Explanation / Answer

d).

Test and CI for One Proportion

Test of p = 0.1725 vs p > 0.1725

                                              Exact

Sample   X    N Sample p 95% Lower Bound P-Value

1       99 500 0.198000         0.169071    0.075

One sided p=0.075

Two sided P=0.139, p/2=0.0695 which is not same as 1 sided p

                                                   Exact

Sample   X    N Sample p         95% CI         P-Value

1       99 500 0.198000 (0.163944, 0.235673)    0.139

e).

two sided power

Power and Sample Size

Test for One Proportion

Testing p = 0.1725 (versus 0.1725)

= 0.1

              Sample

Comparison p    Size     Power

       0.198     500 0.450224

Power and Sample Size

Test for One Proportion

Testing p = 0.1725 (versus 0.1725)

= 0.05

              Sample

Comparison p    Size     Power

       0.198     500 0.335056

When changes from 0.10 to 0.05, power decreases.

f).

one sided test

Power and Sample Size

Test for One Proportion

Testing p = 0.1725 (versus > 0.1725)

= 0.1

              Sample

Comparison p    Size     Power

       0.198     500 0.585442

Power and Sample Size

Test for One Proportion

Testing p = 0.1725 (versus > 0.1725)

= 0.05

              Sample

Comparison p    Size     Power

       0.198     500 0.448831

When power increases when we change from two sided to one sided test.