An owner of a home in the Midwest installed solar panels to reduce heating costs. After installing the solar panels, he measured the amount of natural gas used y y ( in cubic feet) to heat the home and outside temperature x x (in degree-days, where a day's degree-days are the number of degrees its average temperature falls below 65 oF o F ) over a 23-month period. He then computed the least-squares regression line for predicting y from x and found it to be: yˆ= y ^ = 85 + 13x. How much, on average, does gas used increase for each additional degree-day?

What is the value of f(x) = 2.2 for f(-2)?

Use the elimination method to solve the systems of equations.choose the correct ordered pair. 7x+4y=39

Ascientist places 24 cells in a petri dish. she knows the cells grow at an exponential rate, doubling in number every hour. how long will it take (in hours) for there to be 1100 cells in the dish? time to 1100 cells: 5.51832530 hours how long will it take to reach 110 cells? time to 110 cells : 2.1963972 hours what is the average rate of change in the number of cells between 9 hours and 11 hours? average rate of change: cells per hour what is the instantaneous rate of change after 7 hours? instantaneous rate of change: cells per hour note: you can earn partial credit on this problem.