+125 Suppose the velocities of golf swings for amateur golfers are normally distributed with a mean of 95 mph and a standard deviation of 3.9 mph what is the difference in velocities between a golfer whose z score is 0 and another golfer whose z score is -1?
A 1.95 mph
B 2.9mph
C 3.9mph
D 7.8mph
+129849 z score = [ raw score - mean ] / std deviation
So...for the fiirst
[ raw score - 95 ] / 3.9 = 0 multiply throughh by 3.9
raw score- 95 = 0
Raw score = 95 = 95 mph
For the second, we have
[ raw score - 95 ] / 3.9 = -1 multiply through by 3.9
raw score - 95 = -3.9 add 95 to both sides
raw score = 91.1 = 91.1 mph
So....the difference in speeds is
95 - 91.1 =
3.9 mph
