Question

If we know that the length of time it takes a college student to find a parking spot in the library parking lot follows a normal distribution with a mean of 3.5 minutes and a standard deviation of 1 minute, find the point in the distribution in which 75.8% of the college students exceed when trying to find a parking spot in the library parking lot.

A. 2.8 minutes
B. 3.2 minutes
C. 3.4 minutes
D. 4.2 minutes

Answer 1

http://davidmlane.com/hyperstat/z_table.html

Answer 2

Without that site, you can still figure it out.

Z = (x - mean)/standard deviation

In the back of your text, there is a table labeled something like "areas under normal distribution." Find that percentage in the table to determine your Z score. Put the values in the above equation and solve.

I hope this helps a little more.

Answer 3

Thank you for your help bobpursley and PsyDAG.

I believe the answer is 2.8 minutes. However, the wording of the question using 'exceed' is confusing to me. How do you confirm it is indeed 2.8 minutes and not 4.2 minutes.

Thanks again.

Answer 4

If we know carry equal marks library parking lot time it takes college student to nnd a parking spot in the deviation of follows a normal distribution with a mean of 3.5 minut a parking 1 minute, find the probability that a r randomly selected college student will find a spot in the library parking lot in less than 3 minutes