An author receives a contract from a publisher, according to which she is to be paid a fixed sum of $ thousand, plus $ for each copy of her book sold. Her uncertainty about total sales of the book can be represented by a random variable with mean thousand and standard deviation thousand. Answer the following, rounding your answers to two decimal places where appropriate.

(a) Find the mean (in thousands of $) of the total payments she will receive.

(b) Find the standard deviation (in thousands of $) of the total payments she will receive.