A. The cubic function is the best fit to these data. The cubic function is given as

To determine the best fit, we can analyze the patterns in the data. Since the relation appears to be cubic, we will use a cubic function of the form
to model the data.
The cubic function has four coefficients: a, b, c, and d. To find these coefficients, we need four data points. In this case, we have more than four data points, so we can use the method of least squares to fit the cubic function to the data.
Once we find the coefficients, we can use the cubic function to predict the temperature at 5 PM x = 17, as 5 PM is 17 hours after midnight).
The cubic function is written as
, and the coefficients a, b, c, and d will be specific values determined from the data.