In: Statistics and Probability
In the 2017 Community Health Status Survey, area residents were asked how much sitting they do in a day. Of 2036 men who responded, 560 (27.5%) reported sitting at least 8 hours a day. 2183 respondents were female; 502 (23%) reported sitting at least 8 hours. Is there a difference in the proportion of males (population #1) and females (population #2) who spend at least 8 hours a day seated? Test H0: p1 = p2 versus Ha: p1not equal to p2 using αλπηα = 0.01.
z-test statistic =
p-value =
conclusion =
Give a 99% confidence interval for the difference between the proportions (p1 − p2) of men and women who sit more than 8 hours a day.
lower limit = u
pper limit =
The statistical software output for this problem is:
Two sample proportion summary hypothesis test:
p1 : proportion of successes for population 1
p2 : proportion of successes for population 2
p1 - p2 : Difference in proportions
H0 : p1 - p2 = 0
HA : p1 - p2 ≠ 0
Hypothesis test results:
Difference | Count1 | Total1 | Count2 | Total2 | Sample Diff. | Std. Err. | Z-Stat | P-value |
---|---|---|---|---|---|---|---|---|
p1 - p2 | 560 | 2036 | 502 | 2183 | 0.045090344 | 0.013371466 | 3.3721316 | 0.0007 |
99% confidence interval results:
Difference | Count1 | Total1 | Count2 | Total2 | Sample Diff. | Std. Err. | L. Limit | U. Limit |
---|---|---|---|---|---|---|---|---|
p1 - p2 | 560 | 2036 | 502 | 2183 | 0.045090344 | 0.013381046 | 0.010623053 | 0.079557634 |
Hence,
z test statistic = 3.3721
p-value = 0.0007
Conclusion: Reject Ho: Sufficient evidence for difference in proportion
99% confidence interval:
Lower limit = 0.0106
Upper limit = 0.0796