Question

One with a systolic blood pressure greater than 129 is considered to have high blood pressure. A study recorded the systolic blood pressures of 14 randomly selected Americans, which yielded a mean of 131.57 with standard deviation 15.88. Conduct a hypothesis test to see if you can say that Americans, on average, have high blood pressure.

A. Write the hypotheses for this test.

B. What is the test statistic?

C. What is the p-value?

D. Using α = 0.05, decide whether or not to reject the null hypothesis.

E. Based on your decision, is there evidence that Americans, on average, have high blood pressure?

Answer 1

a)

The test hypothesis is

b) Now, the value of test static can be found out by following formula:

c) Using Excel's function =T.DIST(t0,n-1,TRUE), the P-value for t0 = 0.6055 in an power-tailed t-test with 13 degrees of freedom can be computed as

d) Since P = 0.7224 > 0.05, we fail to reject the null hypothesis

e) Yes the Americans on average, have high blood pressure