Question 1081971
the margin of error should be +/-0.13, so 0.13=z*s/sqrt(n)
1.96*s/ sqrt (n)=0.13
1.96*0.4=0.13* sqrt(n), after multiplying through 
divide through by 0.13 and square both sides
n=36.37 which rounds up to 37.  That is unlikely to be changed by using a t-value