In a certain normal distribution of scores, the mean is 40 and the standard deviation is 3. Find the z-score corresponding to a score of 54.
a. 4.67
c. 4.67
b. 18.0
d. 13.33
Please select the best answer from the choices provided

choice a.) 4.67

Step-by-step explanation:

Using the Z-score table.

We have:

mean u = 40

standard deviation s  = 3

for X = 54

Use formula for Z-score:   Z = (X -u)/s

Z-score = Z = (X - u)/s  = (54 - 40)/3 = 14/3 = 4.6667

P(Z > 4.6667) = 0.000003   very close to 0

answer: 88

step-by-step explanation:

the simplified form is

step-by-step explanation:

we want to simplify the expression,

let us change the middle bar to a normal division sign to obtain,

we multiply the first fraction by the reciprocal of the second fraction to obtain,

we factor to obtain,

we cancel the common factors to get,

we simplify to get,

the correct answer is b