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.