I have a sample size of n=175 and mean of μ =6.78 hours. What is the standard deviation of X̄ do you need that 95% of all samples will have to mean within 5 minutes of μ
I used the equation m(margin of error) = (Z*)(σ / √n) so my solution when I plug in the variables and solve is as followed .08=(1.96)(σ /13.229) which gives me 0.58 but the correct answer is 0.041
What am I doing wrong?