6.25 Blood pressure A World Health Organization study

(the MONICA project) of health in various countries reported that in Canada, systolic blood pressure readings have a mean of 121 and a standard deviation of 16. A reading above 140 is considered high blood pressure.

a. What is the z-score for a blood pressure reading of 140?

b. If systolic blood pressure in Canada has a normal distribution, what proportion of Canadians suffers from high blood pressure?

c. What proportion of Canadians has systolic blood pressures in the range from 100 to 140?

d. Find the 90th percentile of blood pressure readings.