4b11. Can someone show me how to do this problem?

Will rate a thumb up for good response thank you (Please circle or highlight answers thx)

The following data relate the sales figures of the bar in Mark Kaltenbach's small bed-and-breakfast inn in Portland, to the number of guests registered that week: Week Guests Bar Sales 1 16 2 $340 $270 $375 $315 12 18 14 3 4 a) The simple linear regression equation that relates bar sales to number of guests (not to time) is (round your responses to one decimal place): Bar Sales = + x guests b) If the forecast is 20 guests next week, the bar sales are expected to be $ (round your response to one decimal place)