Question

A researcher wishes to estimate the number of households with two cars. How large a s proportion will not differ from the true proportion by more than 4%? ample is needed in order to be 95% confident that the sample A previous study indicates that the proportion of households with two cars is 22%.

Answer 1

Answer:

Sample size calculation

Given: p=0.22

For 95%, z=1.96

d=0.04

Sample size = (z²*p*(1-p))/d²

= (1.96²*0.22*0.78)/0.04²

=412.0116

The sample size required= 413 (rounded up).