Question

what is the shortest time spent waiting for a heart waiting that would still place a patient in the top 20% of waiting times. ų =126 á=22.2

Answer 1

(a)

The shortest time spent waiting for a heart that would still place a patient in the top 20% of waiting times is obtained below:

Consider

Procedure for finding the z-value is listed below:

1. From the table of standard normal distribution, locate the probability value of 0.80.

2. Move left until the first column is reached. Note the value as 0.8

3. Move upward until the top row is reached. Note the value as 0.04.

4. The corresponding tow and column values together give the value of z. That is

The intersection of the row and column values gives the area to the left, .

From the “Standard normal table”, the value of z that corresponds to the probability of 0.80 is 0.84.

Mean =126

S.D. = 22.2

Z = (X - μ) / σ
0.84 = (X - 126) / 22.2
X = 126 + 18.648

X = 144.648