In a certain normal distribution of scores, the mean is 40 and the standard deviation is 3. Find the s-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

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

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

hello from mrbilldoesmath!

answer:

a(n) - a(n-1) -3

discussion:

this ones a bit interesting. given a(n) = 5 - 3n consider this:

a(n-1) = 5 - 3(n-1)

          = (5 - 3n) + 3             => but a(n) = 5 - 3n, the first term

          = a(n)   + 3                 => subtract 3 from both sides

a(n-1) -3 = a(n)  

or

a(n) - a(n-1) -3

you,

mrb