Q:

Asa received scores of 72, 97, and 82 on her last three math tests. she needs a mean test score of 82 to qualify for the math team. what is the first step in determining how many points she needs on her next test to qualify for the team?

Accepted Solution

A:
Scores are {72, 97, 82, x} where x is the unknown fourth scoreThey add up to 72+97+82+x = x+251Divide this sum over four because there are four scores we want to average out. We end up with (x+251)/4 = M where M is the mean. Asa wants the mean to be 82, so make M = 82. We can replace M with 82 and solve for x like so(x+251)/4 = M(x+251)/4 = 82x+251 = 4*82x+251 = 328x = 328-251x = 77Asa needs a score of 77 on the fourth test so that the mean of the four tests is 82. If she scores higher than 77 on the fourth test, then the mean will be larger than 82.-----------------------------------Depending on what your teacher is looking for, the first step is to establish your variable. So you would say "let x = fourth score". However, that seems too easy. So perhaps your teacher is looking for the equation (x+251)/4 = 82 or some variant of it.