The question is asking how to calculate the confidence interval for p. The sample size/n is given and the mean of that sample size is given. The confidence interval is 90. I think I am supposed to find the p-value first but I am not sure.
I think the formula is square root (p)- (1-p)/ n right?
But to find p do I use 1-alpha/2? Is 0.10 for confidence interval 90? Like is it 1-0.10/2=.05?