$\backslash$table$[[$Party i$,$No$.$ Guests,Total Cost$],[1,63,$$$1,463$

To get a scatter $(xY)$ chart of the data:

Select the cells in two columns where the data are. $($This assumes that the $x$ values are in the left column a the corresponding $y$ values are in the right column.$)$

Insert tab $>$ Scatter $($XY$)$ chart $...$

Select the chart and then add Chart elements such as Axis Titles, etc.

To get the regression equation, there are $3$ different ways:

Use INTERCEPT $(y-$range, $x-$range$)$ and SLOPE$(y-$range, $x-$range$)$ cell functions.

Note that the $y-$range must be listed first for both of these functions!

Right click on any of the points in your scatter chart and select "Add Trendline..." Then select the Linear trend$/$regression type, and check the box near the bottom of the dialog box that says "Display Equation on chart."

Data tab $>$ Data Analysis $>$ Regression $...$

In the Regression dialog box:

Input Y Range: Click & drag the cursor over the values in the $y$ data column only

Input $x$ Range: Click & drag the cursor over the values in the $x$ data column only

Output Options: Specify where you want the regression output to appear

Residuals: optionally check $1$ or more of the boxes, e$.$g$.,$ Residual Plots

Click OK button $...$

$a$ & $b$ of the regression equation will be listed in the first $2$ rows below "Coefficients"

To get the correlation coefficient, there are $2$ different ways:

Use the CORREL$(x-$range, $y-$range$)$ cell function. This function does not care which range is listed first.

Data tab $>$ Data Analysis $>$ Correlation $...$

In the Correlation dialog box:

Input Range: Click & drag the cursor over values in BOTH columns of data

Grouped by: Select radio button for Columns

Output Options: Specify where you want the results to appear

Click OK button