At the U.S. Open Tennis Championship a statistician keeps track of every serve that a player hits during the tournament.

[answerhappygod]

At the U.S. Open Tennis Championship a statistician keeps track
of every serve that a player hits during the tournament. The
statistician reported that the mean serve speed of a particular
player was 97 miles per hour (mph) and the standard deviation of
the serve speeds was 12 mph. Assume that the statistician also gave
us the information that the distribution of the serve speeds was
mound-shaped and symmetric. What proportion of the player's serves
was between 109 mph and 133 mph?
A.0.317
B.0.1585
C.0.997
D.133