Question

Using Excel and the functions

Insurance companies are interested in knowing the population percent of drivers who always buckle up before riding in a car.

1. When designing a study to determine this population proportion, what is the minimum number you would need to survey to be 95% confident that the population proportion is estimated to within 0.03?
2. If it were later determined that it was important to be more than 95% confident and a new survey was commissioned, how would that affect the minimum number you would need to survey? Why?

Don't forget to show me how you got your answer using excel and this formula sqrt(p'*(1-p')/n) =

Answer 1