3. The function N(x) = 90(0.86)* + 69 can be used to predict the temperature of a cup of hot chocolate in degrees Fahrenheit after x minutes. What is the approximate average rate of change of
the temperature of the hot chocolate, in degrees per minute, over the interval (0,8)?
(1)-9.59
(3) 6.31
(2) -6.31
(4) 9.59