A department of store manager has monitored the number of complaints received per week about the poor service. The probabilities for the number of complaints in a week are shown in the table. Each complaint for the poor service costs $5 to the department. Find the mean and variance of the cost because of the complaints in a week.
Number of Complaints: 0, 1, 2, 3, 4, 5
Probability: 0.14, 0.39, 0.23, 0.15, 0.06, 0.03