Answer:
She needs 77 on her last test to earn an 82 for the quarter.
Step-by-step explanation:
Maria scored 72, 97, and 82 on her first three math tests.
She wants to have a mean score of 82 for the quarter.
Let us assume that she must score x on her last test to earn an 82 for the quarter.
So the average score will be,
\(=\dfrac{72+97+82+x}{4}\)
But the average score is given as 82, so
\(\Rightarrow \dfrac{72+97+82+x}{4}=82\)
\(\Rightarrow 72+97+82+x=82\times 4\)
\(\Rightarrow 72+97+82+x=328\)
\(\Rightarrow x=328-72-97-82\)
\(\Rightarrow x=77\)
