Question

2.

Answer 1

Answer:

66 inches ;

95.44 ;

4

Step-by-step explanation:

Given that:

Normal distribution with;

Mean(m) = 66 inches

Standard deviation (s) = 3 inches

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?

Zscore = ( x - m) / s

x = 63

Zscore = (63 - 66) / 3

Zscore = - 3/3

= - 1

P(Z < - 1) = 0.1587

0.1587 * 25 = 3. 967 = 4