The time a group of high school students arrive home from school each day was found to be normally distributed. The mean time was 3:15pm and the times had a standard deviation of 15 minutes. What is the probability that a student chosen at random arrives home from school before 2:30pm?
Algebra - sarah rox ur sox off, Wednesday, March 5, 2008 at 7:55pm
Algebra - PsyDAG, Thursday, March 6, 2008 at 9:43am
Caculate Z score for this time.
Z = (x - μ)/SD
x =2:30, μ = 3:15, SD = 15
Look up the Z score in the back of your statistics text on a table of areas under the normal distribution to get your probability.
I hope this helps. Thanks for asking.