use formula where lower fence is Q1- 1.5 IQR and upper fence is Q3+1.5 IQR.
7a) Q1 is 30 ,Q2 is 34, Q3 is 40,
IQR is Q3-Q1: 40-30
IQR=10
upper fence is 40+1.5(10)= 55
lower fence is 30-1.5(10) = 15
