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