Question

A special diet is intended to reduce cholesterol level. If the diet is effective, the target is to have the average cholesterol level of this group be below 150. After six months on the diet, an SRS of 28 patients with high cholesterol level had an average cholesterol of = 143, with standard deviation s = 21. Is this sufficient evidence that the diet is effective in meeting the target? Assume the distribution of the cholesterol level for patients in this group is approximately Normal with mean μ. Based on the data, the value of the one-sample t statistic is.

Answer 1

@mathmale Can you please help me?

Answer 2

A.0.33
B.1.76.
C.–1.76.
D.-0.3

Answer 3

Hi, Yana, and good morning!!

Normally I'd do a quick review of "one-sample t statistic" in my trusty Statistics I book, but I'm in California and that nice book is in Rochester, NY.

Could you please look up "one-sample t statistic" and then type in the formula for that here?

Answer 4

Here's a great source of info:

http://lap.umd.edu/psyc200/handouts/psyc200_0810.pdf

You might want to look at that before you go through all the work of typing out that definition of the t-statistic.

Answer 5

That's what I was looking at:)

Answer 6

Great. Now, from the problem statement, please identify the following:\[x-\bar, \mu, s, n\]

Answer 7

That's x-bar, mu, s and n.

x-bar is the sample (SRS) mean.

Answer 8

You'll find that if you correctly substitute the values of these four parameters into the formula for the t-statistic, you'll obtain a result equal to one of the four answer choices.

Answer 9

x-bar=28
s=21? idk..

Answer 10

I'm stuck...I don't know..What do the mu,s,n, mean..I don't get it..

Answer 11

Yes, the sample standard deviation, s, is 21.
But the sample mean is 143, not 28. It's the sample size (n) that is 28.

Answer 12

I knew that....143 was the sample mean...I just didn't want to get it wrong

Answer 13

Yana, please plug in those four parameter values and calculate your t-statistic.