The mean amount spent by a family of four on food per month is $550 with a standard deviation of $85. Assuming that the food costs are normally distributed, what is the probability that a family spends less than $410 per month?
math - PsyDAG, Saturday, November 17, 2012 at 12:46pm
Z = (score-mean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion that relates to your Z score.