In A Random Sample of 678 ADULT MALES 20 TO 34 Years of age, it was deermined that 58 of them have hypertension.

Part C-

You wish to conduct your own study to determine the proportion of adults of 20-35 years old who have hypertension. What sample size would be needed for the estimate to be within 3 percentage points with 95% confidence if you use the point estimate in part a.

part a was obtain a point estimate for the portion. 58/768=.085

Okay this is what I did, .085(1-.085)(1.96/.03)^2 and I got 54.42...

The answer is suppose to be 336, I am wondering what i did wrong here.