9. Incorrect. The answer is true not false

 

Using the following confidence interval formula for large populations (n ≥ 30):

 

Probability (X +/- zc sn-1/2) = 95%

 

Where X = 0.85

zc = 1.96

s = 0.05

n = 50

 

Upper limit = 0.85 + 1.96*0.05* 50-1/2 = 0.865 or 86.5%

Lower limit = 0.85 - 1.96*0.05* 50-1/2 = 0.836 or 83.6%