Question

A grocery store chain has been tracking data on the number of shoppers that use coupons. The data shows that 71% of all shoppers use coupons. 18 times out of 20 these results were considered accurate to within 2.5%

Answer 1

The computation for the confidence level = (18/20) x 100% = 90 %, the E or the margin error = 0.023 and the p = to 0.71. Confidence interval can be achieved by using the formula (p-E, p+E) = (0.71-0.025, 0.71+0.025). Therefore, the confidence interval is (0.685,0.735).

Answer 2

Answer:

90%

Step-by-step explanation:

18/20 = .9

.9*100= 90%