1. A doctor collects data on all the men in her practice. They have an average age of 50 years, with a standard deviation of 18 years. They have an average systolic blood pressure of 150 mmHg, with a standard deviation of 12 mmHg. The two variables have correlation r = 0.6. (a) Using regression, calculate the predicted systolic blood pressure for a man in the practice who is 30 years old: mmHg 50 years old: mmHg 60 years old: mmHg (b) The above predictions all are subject to error. The average size of such errors is about mmHg, and 95% of the predictions we make using regression will therefore be correct to within about mmHg. (c) A man is selected at random from the practice. He is 70 years old, which means that he is SD(s) above the average age of men in the practice. Another way of expressing his relative age is that he is at the percentile of age among all men in the practice. (d) Using regression, we can predict the man from part (c) will have a blood pressure that is SD(s) above average. Therefore, he is predicted to be at the percentile of blood pressure