Question 1147287
Mean =38.9
SD=7.9
For a z-distribution we have z=(x-mean)/SD
We have to find the probability that x lies between 30 and 41 minutes.
Plugging in the values,
z1=(30-38.9)/7.9=-1.1265
z2=(41-38.9)/7.9=0.2658
The required probability=0.604812153-0.129959568=0.4748