Times for a surgical procedure are normally distributed. Method A has a mean of 28 minutes and a standard deviation of 2 minutes for completion.

Question

What is the probability that a surgical procedure conducted by method A takes at most 33 minutes to complete?

Answer 1

this is one of the best sites for your kind of question

http://en.wikipedia.org/wiki/List_of_countries_by_life_expectancy

enter
mean -- 28
SD ---2
click on below, enter 33

I get .99379

Answer 2

Is that site the one you meant to post?

Answer 3

no, sorry, must have missed the "copy" before the "paste"
try this one ....

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