answer a and b please

x - ux t= x - ux Formulas: Z = Sx Vn R2 f = k - 1 1 - R2 n - k a. Suppose a Tesla dealer in Placentia, CA is trying to calculate the probability of his car sale for next week. The dealer knows that the sale of car is normally distributed with mean sale 86 and variance (population variance) 36. What is the probability that the dealer will sell 90 or more cars next week? (12.5) b. Suppose a Ford dealer in Fullerton, CA is trying to calculate the probability of his car sale for next week. The dealer knows that the sale of car is normally distributed with mean 75. However, the variance of car sale is unknown. From weekly data of 20 weeks, the dealer knows the variance is 12. What is the probability that the dealer will sell 77 or more cars next week? (12.5)