Assume the interval 045 085 is a Confidence Interval for pro

Assume the interval (0.45, 0.85) is a Confidence Interval for proportion with n = 26.

A) Find the sample proportion

B) Find the confidence level.

A) Find the sample proportion

p=(0.45+0.85)/2=0.65

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B) Find the confidence level.

Z*sqrt(p*(1-p)/n) = (0.85-0.45)/2 =0.2

--> Z*sqrt(0.65*(1-0.65)/26) = 0.2

--> Z=0.2/0.09354143 =2.13809

So it is P(Z>2.13809) =0.0163 (from standard normal table)

It is 1-0.0163*2=0.9674

i.e. 96.74%