A doctor collects data on all the men in his practice. Their daily potassium intake is 4500 mg/day, with a standard deviation of 1000 mg/day. They have an average systolic blood pressure of 150 mmHg,...

A doctor collects data on all the men in his practice. Their daily potassium intake
is 4500 mg/day, with a standard deviation of 1000 mg/day. They have an average
systolic blood pressure of 150 mmHg, with a standard deviation of 10 mmHg. The
two variables have correlation r = -0.4.
(a) One of the men is at the 25 percentile of potassium intake and 75 percentile of
blood pressure. Relative to all other men at the 25th percentile potassium intake,
this man’s blood pressure is (circle one)
smaller than average
about average
larger than average
Justify your answer using a written explanation and/or a diagram.

(b) A man is selected at random from the practice. His potassium intake is 5500
mg/day, which means that he is _____________ SD(s) above the average
potassium intake of men in the practice. Another way of expressing his relative
potassium intake is that he is at the _______________ percentile of intake among
all men in the practice.
(c) Using regression, we can predict the man from part (b) will have a blood
pressure that is _______________ SD(s) _________________ (choose between
above/below) average. Therefore, he is predicted to be at the ______________
percentile of blood pressure.