SOLUTION: A mom here trying to understand and help her child!! How do you set up and answer this world problem. For the question below, first write the equation or inequality in the f

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Question 639527: A mom here trying to understand and help her child!!
How do you set up and answer this world problem.
For the question below, first write the equation or inequality in the first blank, then perform the calculation and record your answer in the second blank.
Your current grades in Algebra I are 74, 88, 87 and 83. What grade do you need on the next test to raise your averag to at least 85?
__________________________
__________________________

Found 2 solutions by MathTherapy, MathLover1:
Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!
For the question below, first write the equation or inequality in the first blank, then perform the calculation and record your answer in the second blank.
Your current grades in Algebra I are 74, 88, 87 and 83. What grade do you need on the next test to raise your averag to at least 85?
__________________________
__________________________

Since there are already 4 grades, then a total of 5 grades will be used to determine the final average grade.

As the child requires an average of 85, s/he needs to get a total of at least 425 (85 * 5) points

The child has already received a total of 332 (74 + 88 + 87 + 83) points, but would like to acquire at least 425 points

Let's make the final grade the child needs be F

We now have: 332 + F = 425

F, or final grade needed is AT LEAST 93 (425 - 332)

Inequality in the first blank is: highlight_green%28%2874+%2B+88+%2B+87+%2B+83+%2B+F%29%2F5+%3E=+85%29, or %28332+%2B+F%29%2F5+%3E=+85

332+%2B+F+%3E=+425 ---- Cross-multiplying

F+%3E=+425+-+332

Answer in the 2nd blank is: highlight_green%28F+%3E=+93%29

Send comments and “thank-yous” to “D” at MathMadEzy@aol.com

Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

current grades in Algebra I are 74, 88, 87 and 83
What grade (let' it be x) do you need on the next test to raise your average to at least 85?
first you need to know that an average is a sum of all grades divided by number of grades
so, you have
%2874%2B88%2B87%2B83%2Bx%29%2F5=85
%28332%2Bx%29%2F5=85
332%2Bx=85%2A5
332%2Bx=425
x=425-332
highlight%28x=93%29

check:
previous average grade was:%2874%2B88%2B87%2B83%29%2F4=83
if you get 93on the next test, average grade will be
%2874%2B88%2B87%2B83%2B93%29%2F5=425%2F5+=85