Question

The Survey of Study Habits and Attitudes (SSHA) is a psychological test that measures the motivation, attitudes, and study habits of college students. Scores range from 0 to 200 and follow (approximately) a Normal distribution, with mean of 115 and standard deviation 25. A researcher suspects that incoming freshmen have a mean μ, which is different from 115, because they are often excited yet anxious about entering college. To verify her suspicion, she tests the hypotheses
H0: μ = 115
Ha: μ 115.
The researcher gives the SSHA to 100 incoming freshmen and observes a mean score of 119. Assume that the scores of all incoming freshmen are approximately Normal with the same standard deviation as the scores of all college students.
Reference: Ref 13-5

The P-value for this test is
A. 0.0082.
B. 0.1096.
C. 0.0548.
D. 0.8024.

Answer 1

the p value is the chance of observing the test statistic or anything more extreme from the mean

Answer 2

That's what we were given in the first Q right?

Answer 3

so effectively, you want to find P( x > 119 ) and double this value

Answer 4

or it's not the confidence level? In the videos it says it's the probability....

Answer 5

yeah p value is a probability

Answer 6

actualy nvm OL

Answer 7

hmmm....

Answer 8

Yeah I have no idea how to even start this Q... Freshman should have a higher amount as shown by what she was saying being "anxious and nervous" but it could be any of those #'s...

Answer 9

here's a very big hint (pun intended)

the value 119 is very close to 115 (relative to the SD) so the p value is going to be relatively very large

Answer 10

oh crap I dind't even see that 119 lOL.

Answer 11

so D?

Answer 12

yes the p value is close to 80%, so it's basically saying fail to reject the null

Answer 13

But teh thing is the Mean is 115, and the SD is 25, so it would seem it should be alower #?

Answer 14

1 deviation would be 140?

Answer 15

correct, 119 is very close to the mean 115 and it's not even close to being 1 SD away from the mean

Answer 16

oh okay I think I konfused myself by thinking a big number was far away... But the probability means it is close to being correct lol.

Answer 17

damnm the answer wasn't D, oh wells 80 is cool, thanks for the help Jim!

Answer 18

what was it?

Answer 19

Idfk didn't give me the answer.... :( prob B?

Answer 20

oh wait...we're in the xbar distribution aren't we?

Answer 21

IMO racist.

Answer 22

huh?

Answer 23

Exactly.

Answer 24

That's why we hate statistics.

Answer 25

good guess, it is B assuming we're in the xbar distribution

Answer 26

OH WELLLS. Medal for that! :P

Answer 27

gimmeh!:P