Question

Jacob has a mean score of 78 after his first four math tests. He wants to make a B, or an average of 80, in math. What does he need to score on the fifth test to have a mean score of 80? (1 point) Responses 82 82 88 88 94 94 108

Answer 1

To find out what Jacob needs to score on his fifth test to achieve a mean of 80, we can start by calculating the total score he needs after five tests.

1. **Calculate the total score needed for a mean of 80:**
\[
\text{Total score needed} = \text{Mean} \times \text{Number of tests} = 80 \times 5 = 400
\]

2. **Calculate Jacob's current total score after four tests:**
Given that his mean score after four tests is 78:
\[
\text{Current total score} = \text{Mean} \times \text{Number of tests} = 78 \times 4 = 312
\]

3. **Find out what he needs on the fifth test:**
We can determine the score needed on the fifth test by subtracting his current total score from the total score needed:
\[
\text{Score needed on fifth test} = \text{Total score needed} - \text{Current total score} = 400 - 312 = 88
\]

So, Jacob needs to score **88** on his fifth test to achieve an average of 80.