Homework SourseIn a certain population body weights are normally distribute
In a certain population, body weights are normally distributed. Not knowing the sample mean or standard deviation, how many people must be surveyed? Assume that we want 96% confidence that the error is no more than 4 percentage points
In a certain population, body weights are normally distributed. Not knowing the sample mean or standard deviation, how many people must be surveyed? Assume that we want 96% confidence that the error is no more than 4 percentage points
Solution
Given population follows normal distribution
|z| value at 96% confidence interval is (1-0.96)/2 is z* = 2.0537
Margin of error E 4% =0.04
Assume population standar deviation =1
sample size (n) =[ (z*SD)/E]^2=[2.0537*1/0.04]^2 = 2637 (rounded up)
