I m not sure what to do after I find the standard deviation for the following problem the Virginia cooperative extension reports that the mean weight...

I m not sure what to do after I find the standard deviation for the following problem

the Virginia cooperative extension reports that the mean weight of yearling angus steers is 1152 pounds. Suppose the weights of each can be described by a normal model with a Standard deviation of 84 pounds. What percent of steers weigh

A) over 1250

B) under 1200

C) Between 1000-1100 pounds