conversations.from: human
conversations.value: Maria's test scores are 80, 70, and 90. What score does she need to get on a fourth test so that her average score for the four tests is exactly 85?
  Give me a solution to this problem
conversations.from: assistant
conversations.value: She needs to have a total of 4*85=340 points over the four tests.
  She has 80+70+90=240 points so far.
  She needs 340-240=100 on the fourth test.