Maria scored 72, 97, and 82 on her first three math tests. She wants to have a mean score of 82 for the quarter. How many points does she need on her last test to earn an 82 for the quarter
72+97+82+ X/ 4 = 82 72+97+82+X = 328 You multiply both sides by 4 because you are trying to isolate the variable. Then add up the values, 251+X= 328. Then subtract 251 from both sides too get X=77.
