# Calculating the percentage of data contained within points when given the standard deviation

The problem

"The mean value of houses on a street is \S125,000 with a standard deviation of \$5,000. The dataset has a mound shaped distribution. (a) Estimate the percent of houses between \$120,000 and \$135,000. (b) Estimate the percent of houses below \$115,000."

I was given this homework problem on my Statistics one homework and I don't know how to solve this. The book doesn't have any examples of this type of problem. Any assistance would be appreciated.