Ivanna has scored
70
,
65
,
65
,
64
, and
62
on her previous five tests. What score does she need on her next test so that her average (mean) is
69
?
so with her new test, there will be 6 tests
(sum of what you have so far + x)/6 = 69
solve for x
To find out what score Ivanna needs on her next test, we can use the formula for calculating the average (mean). The formula is as follows:
Average = (Sum of all scores) / (Number of scores)
In this case, we have 5 previous test scores: 70, 65, 65, 64, and 62. To find the sum of these scores, we add them together:
70 + 65 + 65 + 64 + 62 = 326
Since we now know the sum of the scores, we can use the formula to find the average:
Average = 326 / 5 = 65.2
Now, we want to find out what score Ivanna needs on her next test to make her average 69. We can set up the following equation:
(326 + x) / 6 = 69
where x represents the score she needs on her next test. To solve for x, we first multiply both sides of the equation by 6 to get rid of the denominator:
326 + x = 414
Next, we subtract 326 from both sides to isolate the x variable:
x = 414 - 326 = 88
Therefore, Ivanna needs to score 88 on her next test in order to have an average of 69.