Question

Patients who have artificial hip-replacement surgery experience pain the first day after surgery. Typically, the pain is measured on a subjective scale using values of 1 to 5. Let x represent the random variable, the pain score as determined by the patient. The probability distribution for x is believed to be as below. (Give your answers correct to two decimal places.)

x 1 2 3 4 5
P(x) 0.09 0.14 0.21 0.17 0.39

(a) Find the mean of x.
Incorrect: Your answer is incorrect. .
Redone, added x which is 15/5=3.0
(b) Find the standard deviation of x.
added all of p(x) and then sqrt the answer which came up with 0.2

Answer 1

Xp(x) +...... = 3.63
sqrt((x^2(px) -3.63^2)) = 1.35