The following data represent the temperature T ( Fahrenheit) in Kansas City, Missouri, x hours after midnight on May 15, 2010.

Hours after Midnight, x ……………………….. Temperature (°F), T

3 ………………………………………………….. 45.0

6 ………………………………………………….. 44.1

9 ………………………………………………….. 51.1

12 ………………………………………………….. 57.9

15 ………………………………………………….. 63.0

18 ………………………………………………….. 63.0

21 ………………………………………………….. 59.0

24 ………………………………………………….. 54.0

(a) Draw a scatter diagram of the data. Comment on the type of relation that may exist between the two variables.

(b) Find the average rate of change in temperature from 9 _AM to 12 noon.

(c) What is the average rate of change in temperature from 3 _PM to 6 _PM?

(d) Decide on a function of best fit to these data (linear, quadratic, or cubic) and use this function to predict the temperature at 5 _PM.

(e) With a graphing utility, draw a scatter diagram of the data and then graph the function of best fit on the scatter diagram.

(f) Interpret the y-intercept.