Find the least squares regression equation using the school year (in number of years after 2000) for the input variable and the average cost (in thousands of dollars) for the output variable. (hint: use desmos) (show work)

Answer-

The least squares regression equation using the school year (in number of years after 2000) for the input variable and the average cost (in thousands of dollars) for the output variable is "y=0.937x+12.765" .

Solution-

The independent variable / input variable= x = Number of years after 2000 ( = year-2000)

The dependent variable / output variable = y = Average cost in thousands of dollars

(The table has been attached herewith.)

To find the regression equation for a group of (x,y) points,

We have to calculate the slope and y-intercept, then we can put those values in the equation y = mx + c ( Slope - Intercept formula)

We know that,

Putting the values from the table,

( ∵ Instead of 150,894 we have to put 150.894 as we have find the line for year and thousands of dollars )

Now, for the y-intercept,

Putting the values,

Now, putting the values of c and m, in the Slope-Intercept formula,

() *0.06

Step-by-step explanation:

Cleo buys x packs of markers, y wide-ruled notebooks, and z college-ruled notebooks.

All spiral-bound notebooks, whether wide-ruled or college-ruled, sell for $1.20 each. This gives expressions : 1.20y and 1.20z

A store sells four-packs of permanent markers in assorted colors for $3.19 per pack. Cleo buys x packs of markers so expression becomes :

(3.19 per pack)

As Cleo buys x packs of markers, y wide-ruled notebooks, and z college-ruled notebooks.

The combined expression becomes:

The store charges a 6% sales tax on Cleo’s total bill. So, expression becomes:

() *0.06