Question

Blood pressure: High blood pressure has been identified as a risk factor for heart attacks and strokes. The proportion of U.S. adults with high blood pressure is 0.3. A sample of 32 U.S. adults is chosen. Use the TI-84 Plus Calculator as needed. Round the answer to at least four decimal places. al. Part 1 of 5 Is it appropriate to use the normal approximation to find the probability that more than 44% of the people in the sample have high blood pressure? It is not appropriate to use the normal curve, since np = 9.6 < 10 and n (1 - p) - 22.4 2 10. Part: 1 / 5 Part 2 of 5 A new sample of 78 adults is drawn. Find the probability that more than 42% of the people in this sample have high blood pressure. The probability that more than 42% of the people in this sample have high blood pressure is 5

Answer 1

Answer:

Given,

p = 0.3

sample n = 32

a)

p = 0.44

It is not appropriate to use normal curve, since np = 32*0.44 = 14.08 > 10 & nq = 17.92 > 10

b)

p^ = 0.42

n = 78

P(p^ > 0.42) = P(z > (0.42 - 0.3)/sqrt(0.3*0.7/78))

= P(z > 2.31)

= 0.0104441 [since from z table]

= 0.0104