319,804 views
15 votes
15 votes
A special diet is intended to reduce the cholesterol of patients at risk of heart disease. If the diet is effective, the target is to have the average cholesterol of this group be below 200. After six months on the diet, an SRS of 18 patients at risk for heart disease had an average cholesterol of 191, with a sample standard deviation 7. What's the t-test statistic (t-score)

User QuinRiva
by
2.8k points

1 Answer

24 votes
24 votes

Answer:

t = -5.4548 with 17 degrees of freedom

Step-by-step explanation:

The t-test statistic can be calculated as:


t=(x-\mu)/((s)/(√(n)))

Where x is the average cholesterol of the sample, μ is the average cholesterol to test, s is the standard deviation and n is the size of the sample. So, the test statistic is


t=(191-200)/((7)/(√(18)))=-5.4548

This test statistic is with (n - 1) degrees of freedom.

So, the answer t = -5.4548 with 17 degrees of freedom

User Mohammed Yaser
by
3.4k points