After his six biology tests, Ruben has a mean score of 78. What Score does Ruben need on the next test to raise his average (mean) to 80?
He has a total score so far of 468.
After the seventh test he wants a total of 560.
560 - 468 = 92
he needs to add 2 points to each of the 6 tests already taken
plus, he needs to score the 80 average
(2 * 6) + 80 = ?
To find out what score Ruben needs on his next test to raise his average to 80, we can use the concept of weighted average.
Let's assume Ruben has already taken 6 biology tests and earned a mean score of 78. This means his total combined score from the 6 tests is 78 * 6 = 468.
To raise his average to 80, Ruben needs to have a total combined score of 80 * 7 = 560.
Therefore, he needs to score 560 - 468 = 92 on his next test to raise his average to 80.
To solve this problem, we need to find out what score Ruben needs on his next test to raise his average to 80.
We are given that after his six biology tests, Ruben has a mean score of 78. We also know that there are a total of seven tests (six tests he has already taken and one test he is yet to take).
To find out the score Ruben needs on his next test to raise his average to 80, we can use the concept of mean or average.
The formula to calculate the mean (average) is:
Mean = (Sum of all scores) / (Number of scores)
In this case, we can set up an equation using the given information. Let's call the score Ruben needs on his next test as 'x'. The sum of all the scores would be the mean multiplied by the number of scores. So, we have:
[(78 * 6) + x] / 7 = 80
Let's solve this equation to find out the score Ruben needs on his next test.
Multiply both sides of the equation by 7 to get rid of the denominator:
[(78 * 6) + x] = 80 * 7
Now, simplify and solve for x:
468 + x = 560
Subtract 468 from both sides:
x = 560 - 468
x = 92
Therefore, Ruben needs to score 92 on his next test to raise his average to 80.