Suppose that a population parameter is 0.1, and many samples are taken from the population. if the size of each sample is 90, which of the following will most likely be the standard deviation of the sample proportions?

I think the answer is Letter C - 0.032.

Given: p - 0.1; n - 90
Required: standard deviation of the sample proportion
Solution: To get the standard deviation of the sample proportion, we will use this formula - std = √p (1 - p) / n Replace the variables with the given values, then simplify.
   std = √0.1 (1 - 0.1) / 90
   std = √0.09 / 90
   std = √0.001
   std = 0.032

How many is in each case if there is 12 in each case it would be 40