SOLUTION
(a) From the information given in the question,
We will select a curve with 58 at its center which represents the mean and
[tex]\begin{gathered} 58-17=41 \\ 58+17=75 \end{gathered}[/tex]
41 and 75 at the left and right sides. That is gotten by subtracting and adding the standard deviation of 17.
Hence the answer is Graph D
(b) The region that represents less than 41 is seen in graph B
Hence graph B is the answer
(c) Option A
The probability is 0.1587 that a randomly selected cell phone plan in this population is less than $41 per month