Question

HELP PLEASE???!

Answer 1

AWESOME!!

Answer 2

You can do it!!

Answer 3

A researcher wishes to determine if aerobic exercise improves mental performance immediately following the exercise. He plans to have high school students participate in 30 minutes of aerobic exercise and then take a standard test of their reasoning skills. Suppose the scores of high school students on this test of reasoning skills immediately after 30 minutes of aerobic exercise follow a Normal distribution with mean μ and standard deviation σ = 4. Suppose also that, in the general population of all high school students, scores on the test of reasoning skills follow a Normal distribution with mean 25 and standard deviation σ = 4. The researcher, therefore, decides to test the following hypotheses.
H0 : μ = 25, Ha : μ > 25
To do so, the researcher has 10,000 high school students do 30 minutes of aerobic exercise and then, immediately following the exercise, take the test. The mean score for these students is = 25.2 and the P-value is less than 0.0001.
Reference: Ref 15-1

It is appropriate to conclude which of the following?
A. The researcher has conclusively proved that, for high school students, 30 minutes of aerobic exercise substantially improves mental performance.
B. The researcher has strong evidence that, for high school students, 30 minutes of aerobic exercise substantially improves mental performance.
C. The researcher has moderate evidence that, for high school students, 30 minutes of aerobic exercise substantially improves mental performance.
D. None of the above

Answer 4

can somebody help me with this?

Answer 5

That is a pretty small p value. It would be hard to argue with it. Where have you discussed using language like "conclusively proved" or "strong evidence"?

Answer 6

right....yeah, I'm not sure. the wording of "conclusively proved" or "strong evidence" throws me off. because p-value is small, we can reject the null hypothesis, right? But, the alpha isn't given in the question

Answer 7

I think the phrase I actually take most exception to is "substantially improves". I can see arguing that the researcher has proved improvement, but not "substantial" improvement.

Answer 8

right, i don't know

Answer 9

If someone told me something "substantially" improves my performance, I would want more than a 0.2/4 =5% standard deviation improvement. So, yeah, reject the null hypothesis, but define what constitutes "substantial improvement".

Answer 10

Maybe all the researcher has proved is that exercise wakes up the students who were about to sleep through the test.

Answer 11

I'm thinking that the answer is b. what do you think?

Answer 12

Frankly, I think the researcher has no evidence of "substantial improvement" and therefore D.

Answer 13

i see what you're saying

Answer 14

An SRS of 20 orangutans is selected, and 65 cc of blood is to be drawn from each orangutan using a 100 cc syringe. In the sample, the mean volume is 64 cc and the standard deviation is 12 cc. Assume that in the population of all such procedures, the amount of blood drawn follows a Normal distribution with mean μ.

We are interested in a 95% confidence interval for the population mean volume. The margin of error associated with the confidence interval is
A. 2.68.
B. 4.64.
C. 5.62.
D. 6.84.

Answer 15

You will need to start a new question thread for each question.

Answer 16

according to my calculator, i got 5.259. what am i doing wrong?

Answer 17

how do i do that?

Answer 18

Sorry.

Answer 19

Go up to "Ask a Question" and put your question in there.

Answer 20

where is "ask a question", I'm new to this!

Answer 21

Upper left hand corner in light grey.

Answer 22

okay thank you!