Question

It has been found that 26% of men 20 years and older suffer from hypertension (high blood pressure) and 31.5% of women are hypertensive. A random sample 150 of each gender was selected from recent hospital records, and the following results were obtained.

Men. 43 patients had high blood pressure

Woman. 52 patients had high blood pressure.

(a) Construct 95% confidence interval for the difference of the two proportion. Round your answer to nearest ten-thousandth. Interpret the result.

(b) Based on 95% confidence interval, does a higher percentage of women have high blood pressure?  Explain.

Answer 1

(a) The 95% confidence interval for the difference of the two proportion is between -0.1651 and 0.0451.

We are 95% confident that the true difference of the two proportion is between -0.1651 and 0.0451.

p1	p2	pc
0.2867	0.3467	0.3167	p (as decimal)
43/150	52/150	95/300	p (as fraction)
43.	52.	95.	X
150	150	300	n
	-0.06	difference
	0.	hypothesized difference
	0.0537	std. error
	-0.1651	confidence interval 95.% lower
	0.0451	confidence interval 95.% upper
	0.1051	margin of error

(b) No, since the confidence interval contains 0, we cannot conclude that a higher percentage of women have high blood pressure.