Question

A store is monitoring the sale price of an item. The table models the daily price, y, in dollars, after a given number of days, x. x (days) 0 1 2 3 4 y (price in dollars) 180 170 140 170 180 Part A: Which type of function best models the data? (5 points) Part B: Explain how to determine the best model. Support your answer using complete sentences. (5 points)

Answer 1

The type of function that best models the data is quadratic

Which type of function best models the data?

From the question, we have the following parameters that can be used in our computation:

x (days) 0 1 2 3 4

y (price in dollars) 180 170 140 170 180

We can see that

As x moves from 0 to 4

The y values decrease to 140 (the vertex) and then increase to 180

Only a quadratic function has this behavior

Hence, the type of function that best models the data is quadratic

How to determine the best model

To determine the best model for the data, we need to do the following

• Understand the movement of points
• If the movements is not clear, using a graph can be helpful to study the pattern
• Once the pattern has been identified, we then determine the best model