Add one and one tenths equals three and one half

The table shows the webster family’s monthly expenses for the first three months of the year. they are $2,687.44, $2,613.09, and $2,808.64. what is the average monthly expenditure for all expenses?

We just started the introduction into circles and i have no idea how to do this.

Complete the solution of the equation. find the value of y when x equals to 28 x+3y=28