I am stuck on this question and need some help with explanations, I put some answers that I came to but I am unsure if correct

10. (8 points) A telemarketer makes six phone calls per hour and is able to make a sale on 30 % of these contacts. During the next two hours, obtain:

(a)The probability of making exactly four sales. (Round the final answer to 4 decimal places.) 0.0723

(b)The probability of making no sales. (Round the final answer to 4 decimal places.)

0.1652

(c)The probability of making exactly two sales. (Round the final answer to 4 decimal places.)

0.2677

(d)The mean number of sales in the two-hour period. (Round the final answer to 1 decimal place.)