The scores Brianna earned on 4 of the 5 science tests she has taken so far this year are listed.
95, 90, 85, 95
She wants the mean of all 5 of her test scores to be 90. What does Brianna need to score on the 5th test to get exactly a mean of 90?
That is not the question i was asking
I mean
x = 450 - (95 + 90 + 85 + 95 )
I suspect you caught that.
👍 0 👎 0
To find out what Brianna needs to score on the 5th test to achieve a mean of 90, we can follow these steps:
Step 1: Calculate the sum of the scores Brianna has received so far.
Sum = 95 + 90 + 85 + 95 = 365
Step 2: Calculate the sum of all 5 test scores to achieve a mean of 90.
Total Sum = Mean × Number of Tests = 90 × 5 = 450
Step 3: Find the score Brianna needs to get on the 5th test.
Score on the 5th test = Total Sum - Sum of First 4 Tests
Score on the 5th test = 450 - 365 = 85
Therefore, Brianna needs to score 85 on the 5th test to achieve a mean of 90 for all 5 of her test scores.
(95 + 90 + 85 + 95 + x ) / 5 = 90
(95 + 90 + 85 + 95 + x ) = 90*5 = 450
so
(95 + 90 + 85 + 95) + x = 450
and
x = 450 - (95 + 90 + 85 + 95 + x )