Please help mewith math

Renita analyzed two dot plots showing the snowfall during the winter months for city a and for city b. she found that the median snowfall is 5 inches less in city a than in city b. the mean snowfall is about 2 inches less in city a than in city b. which explains why there is a difference in the measures of center for the sets of data?

Trish receives $450 on the first of each month. josh receives $450 on the last day of each month. both trish and josh will receive payments for next four years. at a discount rate of 9.5 percent, what is the difference in the present value of these two sets of payments?

An 18% discount on a watch saved a shopper $72. find the price of the watch before the discount