Aril and Dita are wealthy Norwegian business owners who each began making monthly donations to international disaster relief at the same time. Aril donated 150 kr the first month, and the cumulative number of Norwegian kroners she has donated increases by a factor of 2.5 each month. Dita donated 300 kr the first month, and the cumulative number of Norwegian kroners she has donated increases by 400 kro each month. What is the first month in which month will Aril's cumulative donation first exceed Dita's cumulative donation?

4a. is 3 miles every hour

4b. is 1/3 of an hour per mile

step-by-step explanation:

55.44 inches

step-by-step explanation:

part a. assuming a perfectly linear relationship, we can find the slope from the first two data points.

slope = m = (change in rainfall)/(change in years)

= (61.80 -62.33)/(2005 -2004) = -0.53/1 = -0.53

then the point-slope form of the equation of the line can be written as

y = m(x -h) +k . . . . . m = -0.53, (h, k) = (0, 62.33)

y = -0.53x +62.33 . . . x = years after 2004

part b. in 2017, x = 2017 -2004 = 13. then the predicted rainfall is

y = -0.53·13 +62.33 = 55.44 . . inches

the predicted rainfall in 2017 is 55.44 in.