Question

In a study of the accuracy of fast food​ drive-through orders, Restaurant A had

330330

accurate orders and

7474

that were not accurate.

a. Construct a

9090​%

confidence interval estimate of the percentage of orders that are not accurate.

b. Compare the results from part​ (a) to this

9090​%

confidence interval for the percentage of orders that are not accurate at Restaurant​ B:

0.1710.171less than<pless than<0.2320.232.

What do you​ conclude?

Answer 1

a.

100(1-)% confidence interval for population proportion is :

90% confidence interval estimate of the percentage of orders that are not accurate:

b.

90​% confidence interval for the percentage of orders that are not accurate at Restaurant​ B:

If we compare both the intervals , we can see that Confidence interval for Restaurant A overlaps with Confidence interval for Restaurant B. This means that there is not significant difference between proportion of non-accurate orders for Restaurant A and Restaurant B at 10 % level of significance.