A survey of shoppers is planned to see what percentage use credit cards.Prior surveys Suggest 54% of shoppers use credit cards.How many randomly selected shoppers must we Survey in order to estimate the proportion of shoppers who use credit cards to within 1% with 95% confidence?
A)16,471
B)8589
C)20,745
D)6718.3
E)9543

Question

Quizplus · Accepted Answer

To find the sample size needed for a proportion with a given margin of error and confidence level, use the formula: n = (Z^2 * p * (1-p)) / E^2. For 95% confidence, Z is 1.96. Here, p = 0.54 and E = 0.01. Calculating gives approximately 9543.

A Survey of Shoppers Is Planned to See What Percentage