An author receives a contract from a publisher, according to which he is to be paid a fixed sum of $9,000 plus $2.25 for each copy of his book sold. His uncertainty about total sales of the book can be represented by a random variable with a mean of 25,000 and a standard deviation of 7,500. Find the mean and standard deviation of the total payments he will receive. - The mean of the total payments he will receive is $|:|. The standard deviation of the total payments he will receive is $|:|