Charlie has scored
76
,
87
,
69
, and
74
on his previous four tests. What score does he need on his next test so that his average (mean) is
77
?
(sum of 4 tests + x)/5 = 77
45.8
To find out what score Charlie needs on his next test in order to have an average of 77, we can use the formula for calculating the average or mean:
Average = (Sum of all scores) / (Number of scores)
In this case, Charlie has already taken 4 tests and wants to find out the score he needs on his fifth test. So, he has a total of 4 test scores.
Let's calculate the sum of the four test scores:
Sum = 76 + 87 + 69 + 74 = 306
To find the score Charlie needs on his next test, we can rearrange the formula as follows:
Score Needed = (Average x Number of scores) - Sum
Plugging in the values we have:
Score Needed = (77 x 5) - 306
Score Needed = 385 - 306
Score Needed = 79
Therefore, Charlie needs to score a 79 on his next test in order to have an average of 77.