A marketing researcher for a phone company surveys 100 people and finds that that proportion of clients

Question:

A marketing researcher for a phone company surveys 100 people and finds that that proportion of clients who are likely to switch providers when their contract expires is 0.15.
a) What is the standard deviation of the sampling of the proportion?
b) If she wants to reduce the standard deviation by half, how large a sample would she need?
Distribution
The word "distribution" has several meanings in the financial world, most of them pertaining to the payment of assets from a fund, account, or individual security to an investor or beneficiary. Retirement account distributions are among the most...