Question

When designing a study to determine this population proportion, what is the minimum number of drivers you would need to survey to be 95% confident that the population proportion is estimated to within 0.04

Answer 1

Answer: 601

Explanation:

The formula to find the minimum sample size(n) , if the prior population proportion is unknown:

`n=0.25((z^c)/(E))^2`, where E = margin of error ,
`z^c` = critical z-value for confidence level c.

Given : E = 0.04

Z-value for 95% confidence = 1.96

So, the minimum sample size required =
`0.25((1.96)/(0.04))^2=0.25(49)^2`

`= 0.25* 2401=600.25\approx601`

Hence, the minimum sample size required = 601