Question #2008589: T-test Hypothesis Testing


Question: The following data (and partial analysis) on blood pressure was gathered at an employer health fair. A sample of 92 employees were screened and their blood pressures and sex were recorded (also pulse, height and weight). SYST= systolic pressure, DIAST = diastolic pressure (both in mm of mercury); SEX = 1 for males and 0 for females. Normally, a person’s systolic pressure is higher than his/her diastolic pressure. The company would like to know if there are any interesting patterns in this data.

OBS SYST DIAST SEX systdev systdev2 sexdev sexdev2 syst-sex
1 108 78 1 -13.96 194.78 0.4783 0.2287 -6.6749
2 108 76 1 -13.96 194.78 0.4783 0.2287 -6.6749
3 108 68 0 -13.96 194.78 -0.5217 0.2722 7.2817
4 106 60 0 -15.96 254.61 -0.5217 0.2722 8.3251
5 124 90 1 2.04 4.18 0.4783 0.2287 0.9773
6 110 78 0 -11.96 142.96 -0.5217 0.2722 6.2382
7 126 84 0 4.04 16.35 -0.5217 0.2722 -2.1096
and many more …
86 110 80 0 -11.96 142.96 -0.5217 0.2722 6.2382
87 104 70 0 -17.96 322.44 -0.5217 0.2722 9.3686
88 126 86 0 4.04 16.35 -0.5217 0.2722 -2.1096
89 172 114 1 50.04 2504.35 0.4783 0.2287 23.9338
90 150 100 1 28.04 786.44 0.4783 0.2287 13.4121
91 136 78 1 14.04 197.22 0.4783 0.2287 6.7164
92 112 70 0 -9.96 99.13 -0.5217 0.2722 5.1947
SUM 11220 7502 48 0.00 23223.8 0.00 22.96 316.09

systdev = deviation from the mean systolic pressure

systdev2 = systdev squared

sexdev = deviation from the mean of sex

sexdev2 = sexdev squared

diasdev= deviation from the mean of diastoylic pressure

diasdev2 = diasdev squared

syst-sex = product of the deviations from the mean of systolic pressure and sex

S diasdev = 0.0 S diasdev2 = 9585.69 Sdiasdev*sysdev= 11190.25 Sdiasdev*sexdev = 287.17

a) Find the mean systolic pressure for the employees in this sample.

b) Find the standard deviation of systolic pressure for the employees in this sample.

c) Find the correlation coefficient between systolic pressure and sex for the employees in this sample.

d) Interpret the meaning/significance of the correlation coefficient found in part c. Why is this a useful piece of information?

Solution: The solution consists of 486 words (3 pages)
Deliverables: Word Document

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