SOLUTION: Hi can you please help me solve; I added all three number then divide, what do I do after that? Jacqui has gradess of 88 and 77 on her first two algebra tests. If she wants a

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Question 553107: Hi can you please help me solve; I added all three number then divide, what do I do after that?

Jacqui has gradess of 88 and 77 on her first two algebra tests. If she wants an average of at least 71, what possible scores can she make on her third test?
Thank you...
Found 3 solutions by nerdybill, jim_thompson5910, solver91311:
Answer by nerdybill(7384)   (Show Source):
You can put this solution on YOUR website!
Jacqui has gradess of 88 and 77 on her first two algebra tests. If she wants an average of at least 71, what possible scores can she make on her third test?
Let x = score of third test
then
(88+77+x)/3 >= 71
(165+x)/3 >= 71
165+x >= 213
x >= 213-165
x >= 48
she must have a score of 48 or greater

Answer by jim_thompson5910(35256)   (Show Source):
You can put this solution on YOUR website!
(88+77+x)/3 > 71

88+77+x > 71*3

88+77+x > 213

165+x > 213

x > 213-165

x > 48

So she needs at least a 48 on the third test.

Answer by solver91311(24713)   (Show Source):
You can put this solution on YOUR website!

To find the average of three numbers, you add the numbers and divide by 3. But if you want that average of three numbers to be a particular thing, namely 71 in this case, you multiply by 3 to get the sum of the three numbers. 3 times 71 is 213. Now you have two of her scores, 88 and 77. 88 plus 77 is 165. That means the third test must be at least 213 minus 165 or 48. Presuming that 100 is the maximum score possible, the score, , on the third test must be in the interval:

And replace the upper limit number if the maximum possible score is other than 100.

John

My calculator said it, I believe it, that settles it