Question

Must be done in Excel with the functions. Show how you got your answer!

The average height of young adult males has a normal distribution with standard deviation of 2.5 inches. You want to estimate the mean height of students at your college or university to within one inch with 93% confidence. How many male students must you measure?

Answer 1

Solution

standard deviation =s =   =2.5

Margin of error = E = 1

At 93% confidence level the z is ,

Z/2= 1.812 ( Using z table )

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

n = ( 1.812* 2.5 / 1 )2

n =20.52

Sample size = n =21

#Excell

z	-1.81191
s	2.5
E	1
n=(z*s/E)^2	20.51888

Z=NORMSINV(0.07/2)

# 21 male students must you measure