A.) If a horse is chosen at random, Expected height will be equal to the mean of the distribution = 66 inches
B.) percentage horses who are between 60 and 72 inches
Zscore = ( x - m) / s
x = 60
Zscore = (60 - 66) / 3
Zscore = - 6/3
= - 2
P(Z < - 2) = 0.0228
Zscore = ( x - m) / s
x = 72
Zscore = (72 - 66) / 3
Zscore = 6/3
= 2
P(Z < 2). = 0.9772
Between 60 and 72
0.9772 - 0.0228 = 95.44
c) In a particular year there are 25 horses running in the Melbourne Derby. How many of these would you expect to have a height of less than 63 inches?
To find the relation between them, you need transform them to the same currency. Let's transform them to cents. $3.60 = 360 cents. One quarter is 25 cents, and one nickel is 5 cents.