14 a. (ii) Substitute the data into the usual formula that is sure to be in your notes and/or textbook.
14 b. Let X be the discrete random variable integers from 1 to 50. You're told that sd(X) = 14.43 => Var(X) = (14.43)^2.
You're expected to know that Var(aX + b) = a^2 Var(X) => sd(aX + b) = |a| sd(X).
(i) a = 1/2, b = 0.
(ii) a = -1, b = 0.
(iii) a = 1, b = 99.
|a| means the magnitude of a.
14 b. (i) The data is given by X/2 therefore sd = 1/2 sd(X) = 1/2 (14.43) = ....
(ii) The data is given by -X therefore sd = |-1| sd(X) = sd(X).
(iii) The data is given by X + 99 therefore sd = sd(X).