Question 1201407
claim is p = .95
sample size is 300
p from the sample is 240 / 300 = .8
95% confidence interval has z-score = plus or minus 1.96
z-score formula is z = (x-m)/s
z is the z-score
x is .8
m is .95
s is the standard error = sqrt(.95 * .05 / 300) = .0125830574
z-score formula becomes z = (.8-.95)/.0125830574 = -11.92.
this is well beyond the critical z-score of -1.96, indicating the results are significant.
the conclusion is that the roportiong is not .95, but more than likely something below that.