Posted by jonathan on Friday, November 30, 2012 at 4:53pm.
The time per week a student uses a lab computer is normally distributed, with a mean of 6.2 hours and a standard deviation of 0.9 hour. A student is randomly selected.
a. Find the probability that a student uses a lab computer less than 4 hours per week.
b. Find the probability that a student uses a lab computer between 5 and 7 hours per week.

Statistics  PsyDAG, Saturday, December 1, 2012 at 1:48pm
Z = (scoremean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions/probabilities related to the Z scores. 
Statistics  james, Monday, August 26, 2013 at 7:44pm
2.376

Statistics  Anonymous, Monday, March 14, 2016 at 9:24pm
25