Posted by **Mike** on Sunday, February 20, 2011 at 7:04pm.

I need help on this question i am confused. I don't think the answers i got are right

The 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?

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

## Answer this Question

## Related Questions

- Stats 330- HELP - I need some help on this question it has two parts but i can'...
- Statistics - Is this right? and how can I break it down if needed? A factory’s ...
- algebra - John has 36 books in his locker. He has text books,library books, and ...
- English - 1. We should not scribble in books in the library. 2. We should not ...
- Math - Amanda checked out 7 fiction books from the library. She also checked out...
- 12 - A factory’s worker productivity is normally distributed. One worker (worker...
- statistics - A widget factory's worker productivity is normally distributed. one...
- 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 ...