Z = (score-mean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to the Z score. Multiply by 100.
A construction zone on Kings Road has a posted speed of 45 kilometers per hour. The speeds of vehicle passing through this construction zone are normally distributed with a mean of 46 kilometers per hour and a standard deviation of 4 kilometers per hour. Find the percentage of vehicles passing through this construction that are
i) Exceeding the posted speed limit.
ii) Traveling at speeds between 50 and 55 kilometers per hour
2 answers
42
3 answers