Suppose that the travel time from your home to your office

[TomJerry]

Question:
Suppose that the travel time from your home to your office is normally distributed with mean 40 minutes and standard deviation 7 minutes. If you want to be 95% certain that you will not be late for an office appointment at 1p.m. what is the latest time that you should leave home?

Solution

here mean = 40 S.D=7

using Z = (X - 40)/7²

but how should is calculate the minumum time?

 

[honestrosewater]

You're looking for an interval. 95% of the area under the normal curve lies within how many SDs of the mean?

 

[moonman239]

Hint: Chebyshev's theorem