Question

The accompanying table shows the average salary for baseball players since 1984.Use quadratic regression and write your equation (use y= in your answer and round your a, b and c values to the nearest hundredth place) example: y=12.25x^2+3.29x+612.25

Answer 1

From the table given for the average salary for baseball players since 1984, by ploting the number of years since 1984 on the horizontal axis and the average salary (thousands of dollars) on the y-axis, the graph below is given

By modelling the gragh using quafdratic regression, the equation of the curve is

$\begin{gathered} y=ax^2+bx+c \\ \text{ Where } \\ a=14.45 \\ b=4.46 \\ c=313.59 \end{gathered}$

Substitute the values of a,b and c in the general quadratic regression equation to get the equation of the curve

$\begin{gathered} \text{The equation is} \\ y=14.45x^2+4.46x+313.59 \end{gathered}$