Question

steven received scores of 70, 95, and 80 on his last three math tests. he needs a mean test score of 80 to qualify for the math team. how many points does he need on his last test to qualify for the team? steven needs total points to have a mean score of 80. steven has points so far. steven needs to score at least points on his last test to qualify for the team.

Explanation:

Step1: Calculate total points needed

Since the mean score of 4 tests should be 80, and the formula for the mean $\bar{x}=\frac{\sum_{i = 1}^{n}x_{i}}{n}$, where $n = 4$ and $\bar{x}=80$. The total points needed is $80\times4=320$.

Step2: Calculate points so far

Add the scores of the first three tests: $70 + 95+80=245$.

Step3: Calculate score needed on last test

Subtract the points so far from the total points needed. Let the score on the last test be $x$. Then $x=320 - 245 = 75$.

Answer:

Steven needs 320 total points to have a mean score of 80.
Steven has 245 points so far.
Steven needs to score at least 75 points on his last test to qualify for the team.