Just multiply.
11.76 * 23.5= 276.36
So Mike earned $276.36 last week
The mean of the data is given

The variance of the data is given

9/50 is the answer I think!
I converted 9/10 to decimal to make it easier for me to solve and got 0.9
I divided 0.9 by 5 and got 0.18
I converted 0.18 to fraction and got 9/50