Firts questions is needed for these 2

Use the following information to answer the next three questions: Medical records at a doctor's office reveal that 21% of adult patients have food allergies. Select a random sample of 200 adult patients and let P = the proportion of individuals in the sample who have allergies. 7. Calculate the mean and standard deviation of the sampling distribution of P. 8. Interpret the standard deviation from problem 7. 9. Calculate the probability that a random sample of 200 adult patients will give a result below 18%