Monday

March 30, 2015

March 30, 2015

Posted by **John** on Thursday, March 10, 2011 at 2:20pm.

The NDSU library checks out an average of 320 books per day, with a standard deviation of 75 books. Suppose a simple random sample of 30 days is selected for observation.

What is the probability that the sample mean for the 30 days will be between 300 and 340 books?

Answer

0.4279

0.2128

0.8558

0.1064

0.9279

There is a 90% chance that the sample mean will fall below how many books?

Answer

323.5

416.0

342.5

337.5

443.4

- Stats 330- HELP -
**PsyDAG**, Friday, March 11, 2011 at 11:29amZ = (mean1 - mean2)/standard error (SE) of difference between means

SEdiff = √(SEmean1^2 + SEmean2^2)

SEm = SD/√(n-1)

If only one SD is provided, you can use just that to determine SEdiff.

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to the Z scores.

**Answer this Question**

**Related Questions**

Statisics - I need help on this question i am confused. I don't think the ...

algebra - John has 36 books in his locker. He has text books,library books, and ...

Math - Amanda checked out 7 fiction books from the library. She also checked out...

algebra ll - The number of books checked out from the library varies directly ...

math - kyle had 36 books in hislocker. some were library books, some were ...

math - kyle had 36 books in hislocker. some were library books, some were ...

math - kyle had 36 books in hislocker. some were library books, some were ...

whole number - At the end of the year, a library reported 32 books lost or ...

English - 1. We should not scribble in books in the library. 2. We should not ...

math - If a student scored an average of 60% on a test, what score would he/she ...