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%