Question

The systolic blood pressure of adults in the USA is nearly normally distributed with a mean of 118 and standard deviation of 17 . Someone qualifies as having Stage 2 high blood pressure if their systolic blood pressure is 160 or higher. a. Around what percentage of adults in the USA have stage 2 high blood pressure? Give your answer rounded to two decimal places. % b. If you sampled 2000 people, how many would you expect to have BP> 160? Give your answer to the nearest person. Note: I had a bit of an issue encoding rounded answers, so try rounding both up and down if there's an issue! people c. Stage 1 high BP is specified as systolic BP between 140 and 160. What percentage of adults in the US qualify for stage 1? % d. Your doctor tells you you are in the 30th percentile for blood pressure among US adults. What is your systolic BP? Round to 2 decimal places. lbs

Answer 1

Let X be the systolic blood pressure of adults

X ~ N(118, 17)

a) The percentage of adults in the USA have stage 2 high blood pressure

= 0.5-0.4932 =0.0068

Answer: 0.68 % of adults in the USA have stage 2 high blood pressure

b) If the sample size is n = 2000

The expected number of adults have BP>160 = np = 2000*0.0068 =13.6

c)

Answer: 9.17% of adults in the US qualify for stage 1.

d) For 30th percentile , the critical value of Z is -0.524

Answer: For 30th percenile the systolic BP is 109.09