Answer:
t = -1.428
Step-by-step explanation:
Average blood pressure among people with high responsibility jobs = u = 140 mm
Number of people sampled for the study = n = 51
Average blood pressure of the sample = x = 139 mm
Standard deviation of the sample = s = 5 mm
The claim is that practicing yoga decreases the blood pressure. So we have to test that after practicing yoga, the average blood pressure will be lesser than 140. Based on this we can formulate the null and alternate hypothesis as:
Null Hypothesis:
Alternate Hypothesis:
Since population standard deviation is not known, we cannot use z-distribution for this test. We are given the value of sample standard deviation, so t-test will be used for this case.
Test statistic is calculated as:
Using the values in this formula gives us:
Therefore, the value of test statistic is -1.428