Posted by **jen** on Wednesday, January 14, 2009 at 3:37pm.

The time (sec) that it takes a librarian to locate an entry in a file of records on checked-out books has an exponential distribution with lambda symbol=0.5.

a)What proportion of all location times are less than 20 sec? At most 20 sec? Atleast 25 sec/ Between 10 sec and 25 sec?

I know the function is f(x)=0.5e^(-0.5x). If I take the integral of the function from 0 to 20, will that give me the answer. Because I got 1, so can you please check if 1 is the right answer for P(x<20).

Then less than 20 is: p(x<20)

betwen 10 and 25 is P(10<x<25)

how do I write at most 20 and at least 25?

## Answer this Question

## Related Questions

- operating system - The proprietor serves an average of 800 students a day, with ...
- Statistics - The head librarian claims that books have been checked out an ...
- statistics - The time that it takes a randomly selected job applicant to perform...
- 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 ...
- Stats - The time that it takes a randomly selected job applicant to perform a ...
- sdu - . A man finds that two things cause him to wake up at night-noise or ...
- Statistics (Poisson) - Cars arrive at a toll booth according to a Poisson ...
- Statistics - Hi folks, I'm having trouble with figuring out the intensity matrix...
- English - He checked out the books yesterday from the library. (Is this correct...

More Related Questions