The National Health and Nutrition Survey reported that 30 % of adults in the United States have hypertension (high blood pressure). A sample of 25 adults is studied. Give the final answers in 3 decimal places.

1. What is the probability that exactly 6 of them have hypertension?

2. What is the probability that fewer than 4 have hypertension?

3. Would it be unusual if more than 10 of them have hypertension?

4. What is the mean number who has hypertension in a sample of 25 adults?

5. What is the standard deviation of the number who has hypertension in a sample of 25 adults?