Due to launching of iPhone 13, an iPhone seller has lowered the prices on iPhone 12 in order to clear the \"leftover inventory\". With reduced prices, the iPhone seller estimates the following probability distribution of total number (X) of iPhone 12 that will be sold at various prices on a given day: X 3 4 5 6 7 n a. What is the expected number of iPhone 12 that the iPhone seller will sell on a given day? (4 marks) b. Given the probability distribution above, what is the expected variance of Variable X? (4 marks} c. Given the probability distribution above, what is the standard deviation of the Variable X? (2 marks) Note: You are required to submit your workings and calculations to the space below for this