I need help understanding and solving the following problem:

8. Over the last 11] years, a company's annual earnings increased year over year seven times and decreased year over year three times. You decide to model the number of earnings increases for the next decade as a binomial random variable. a. What is your estimate of the probability of success, dened as an increase in annual earnings? For Parts b, c, and d of this problem, assume that the estimated probability is the actual probability for the next decade. b. What is the probability that earnings will increase in exactly 5 of the next It] years? c. Calculate the expected number of yearly earnings increases during the next It] years. d. Calculate the variance and standard deviation of the number of yearly earnings increases during the next 1!] years