Answer:
Ricky scored 700 points the 4th time.
Explanation:
By definition the average formula is:

where x are the samples of the data set and n the numbers of elements in the set.
In this case:
- average = 650
- x₁ + x₂ + x₃ = 1900
Replacing the data on the general formula:

//multiply both sides of the equation by 4.

//substract 1900 in both sides of the equation.