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Your math test scores are 68, 78, 90, and 91. What is the lowest score you can earn on the next test and still achieve an average of at least 85?

Respuesta :

Assuming the grade won't be rounded up or down to the nearest whole point, our cumalitive points would have to add up to 425. We can find this by multiplying the average we want (85%) by the total possible points (500).

.85*500=425

We then create this equation where x=fifth test score.

68+78+90+91+x=85

Then solve for x.

68+78+90+91+x=425
327+x=425
x=98

Thus, the minimum score on the last test would have to be a 98 to achieve an average of 85.


However, if the final grade is rounded, the new average we have to achieve is actually an 84.5%. Just follow the same steps as before:

.845*500=422.5
68+78+90+91+x=422.5
327+x=422.5
x=95.5

So in that scenario, you would be able to squeeze by with a 95.5 on that test.

The lowest score you can earn on the next test and still achieve an average of 85 is 98.

From the question, the math test scores are 68, 78, 90, and 91.

To determine the lowest score you can earn on the next test and still achieve an average of at least 85,

For the average of the test scores to be at least 85, that means the sum of the test scores divided by number of tests should be at least 85.

First, let us calculate the score that will give an average of 85.

Let the score be x

Then,

[tex]\frac{68+78+90+91+x}{5}=85[/tex]

[tex]\frac{327+x}{5} = 85[/tex]

Multiply both sides by 5

[tex]5\times \frac{327+x}{5} = 5\times 85[/tex]

[tex]327+x= 425[/tex]

Subtract 327 from both sides

[tex]327-327+x= 425-327[/tex]

∴ [tex]x= 98[/tex]

The score that will give an average of 85 is 98.

Hence, the lowest score you can earn on the next test and still achieve an average of 85 is 98.

Learn more here: https://brainly.com/question/13555316

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