Answer: 974
Step-by-step explanation:
Given : Significance level : [tex]\alpha: 1-0.85=0.15[/tex]
Using the standard normal distribution table for z,
Critical value for significance level of [tex]\alpha:0.15[/tex] : [tex]z_{\alpha/2}= 1.44[/tex]
Sample mean : [tex]\overline{x}= 3.8[/tex]
Standard deviation : [tex]\sigma= 1.3[/tex]
Margin of error : E=0.06
The formula to find the minimum sample size is given by :-
[tex]n=(\dfrac{z_{\alpha/2}\ \sigma}{E})^2[/tex]
i.e .[tex]n=(\dfrac{(1.44)(1.3)}{0.06})^2=973.44\approx974[/tex]
Hence, the minimum number of males over age 25 they must include in their sample = 974
