Question

Suppose that the known standard deviation of the plasma volume of a randomly sampled male is 7.5 ml/kg. If you wanted to find a 99% confidence interval for the mean plasma volume in male firefighters with a maximum margin of error of 2.5, what sample size would be necessary?

z =  

n (unrounded)=

n =

Thank you!

Answer 1

Solution :

Given that,

standard deviation =s =   =7.5

Margin of error = E = 2.5

At 99% confidence level the z is,

= 1 - 99%

= 1 - 0.99 = 0.01

/2 = 0.005

Z/2 = 2.576

sample size = n = [Z/2* / E] 2

n = ( 2.576* 7.5 /2.5 )2

n =59.72

n=60