Question 460554: You want to estimate, with 95% confidence, the population proportion of U.S. adults who drive a car. Your estimate must be accurate within 2% of population proportion. No preliminary estimate is given. Find the minimum sample size needed. Find the minimum sample size needed, using prior study showing that 67% of U.S. adults drive a car.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! You want to estimate, with 95% confidence, the population proportion of U.S. adults who drive a car. Your estimate must be accurate within 2% of population proportion. No preliminary estimate is given. Find the minimum sample size needed. Find the minimum sample size needed, using prior study showing that 67% of U.S. adults drive a car.
-----------------
n = [z/E]^2*pq
------
n = [1.96/0.02]^2*0.67*0.33
= 2124 when rounded up
======================================
Cheers,
Stan H.
============
|
|
|
