Evian's average no five tests were 90%. The average of the four highest test scores was 93%, and the average of the four lowest test scores was 87.75$. What was the sum of the lowest mark and the highest mark?
Evian's average mark for all 5 tests was 90%.
this was the sum of the 5 test scores divided by 5.
the total mark for all 5 tests was therefore 90 * 5 = 450%.
similarly the total mark for the 4 highest test scores was 4 * 93 = 372%
similarly, the total mark for the 4 lowest test scores was 4 * 87.75 = 351%
subtract the 4 lowest test scores from the total test score to get the highest test score.
subtract the 4 highest test scores from the total test score to get the lowest test score.
you get the highest test score = 450 - 351 = 99%
you get lowest test score = 450 - 372 = 78%
the total of the highest test score and the lowest test score is 177%.
To find the sum of the lowest mark and the highest mark, we need to determine the values of the lowest mark and the highest mark.
We know that Evian's average of the five tests was 90%. This means that the sum of all five test scores is 5 * 90 = 450.
We also know that the average of the four highest test scores was 93%. To find the sum of the four highest test scores, we multiply the average (93) by the number of tests (4) to get 93 * 4 = 372.
Similarly, the average of the four lowest test scores was 87.75. To find the sum of the four lowest test scores, we multiply the average (87.75) by the number of tests (4) to get 87.75 * 4 = 351.
Now, to find the lowest mark and the highest mark, we subtract the sum of the four lowest test scores from the overall sum of the five test scores: 450 - 351 = 99.
Therefore, the sum of the lowest mark and the highest mark is 99 + 372 = 471.
If the low score was x and the high score was y, then
x+4*93 = 5*90
4*87.75 + y = 5*90
x+y = 5*90-4*93 + 5*90-4*87.75 = 177