A sample of fifth-grade classes was studied in an article. One of the variables collected was the class size in terms of student-to-faculty ratio. The student-to-faculty ratios of the 73 fifth-grade classes sampled have a mean of 16.82 and a standard deviation of 2.31 . Complete parts (a) through (d) below.
 

a. Construct the graph shown below. x-3s x-25 i-s **s *+25 *+ 3s x- 3s = x+s x-2s = x+ 2s = x-s = x+ 3s (Type integers or decimals. Do not round.)