Karen has an 86% average after 4 grades, what grade does she need to get in order to bringer average up to an 88%?
I need a formula to solve the question.... If anyone has a clue I would love it
I think its ..
a+b+c+d/4=86
86x4=344
a+b+c+d=344
a+b+c+d+e=(88x5)
a+b+c+d+e=440
440-344=96
I THINK THE ANSWER IS 96
explain how you can use multiplication to help you find 20 divide by 5
explain how you can use multdivide5 iplication to help you find 20
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20x .25
To determine the grade Karen needs to achieve in order to raise her average to 88%, we can follow a step-by-step process:
Step 1: Determine the total number of grades taken so far.
Since Karen has taken 4 grades, the total number of grades taken is 4.
Step 2: Calculate the total average points earned so far.
Karen's average after 4 grades is 86%, so the total average points earned is 86% multiplied by 4 (86% * 4 = 344%).
Step 3: Determine the number of grades that would yield the desired average.
To find out the number of grades Karen needs to have an average of 88%, we'll use the weighted average formula. The formula is:
(New average * Total number of grades taken) - (Total average points earned so far) = Grade needed * New grade weight
Thus, the equation becomes:
(88% * (4 + x)) - 344% = x * 100%
Here, "x" represents the number of additional grades Karen needs to take, and "100%" represents the new grade weight since each grade has equal weight.
Step 4: Solve the equation to find the number of additional grades needed.
Let's solve the equation:
(88% * (4 + x)) - 344% = x * 100%
First, distribute the 88%:
(88% * 4) + (88% * x) - 344% = x * 100%
Combine like terms:
(352%) + (88% * x) - 344% = x * 100%
Subtract "x * 100%" from both sides:
(88% * x) - 344% = x * 100% - (352%)
Simplify the right side:
(88% * x) - 344% = x * 100% - 352%
Now, subtract "x * 100%" from both sides:
(88% * x) - 344% + (x * 100%) = -352%
Combine like terms:
(88% * x) + (x * 100%) = -352% + 344%
Simplify the left side:
(88% * x) + (x * 100%) = -8%
Rearrange the equation:
(88% * x) + (100% * x) = -8%
(88% + 100%) * x = -8%
Combine like terms:
188% * x = -8%
Now, isolate "x" by dividing both sides of the equation by 188%:
x = (-8%) / 188%
Divide to calculate the value of "x":
x ≈ -0.0426
Step 5: Interpret the result.
The result "x ≈ -0.0426" implies that Karen would need to take a negative number of grades, which is not possible. Since fractions of grades are not feasible, this means that Karen cannot raise her average from 86% to 88% immediately by taking additional grades. She would need to earn a higher grade in one of her future assignments or exams to bring her average up to 88%.