Question

Shriram earned the following scores on his algebra exams: 94, 73, 89, and 95. What's the lowest score he can get on his fifth exam to have an exam average of at least 90? Type in your numerical answer only. Do not type any words or letters with your answer.

Answer 1

99

Explanation:

The formula for average is sum of the numbers/the number of numbers.

In this case, we don't know the number, so we have to substitute it for x.

So our formula, for now, would be 94+73+89+95+x/5. Since there are 5 numbers in total, that is our denominator.

Okay, since the exam average has to be at least 90, it would have to be greater than or equal to 90.

So our final equation would be 94+73+89+95+x/5≥ 90.

Now we solve!

First we add 94+73+89+95, which is 351.

So our equation would look like this: 351+x/5≥90.

Now we multiply 5, so we have to do it on both sides.

Our expression would look like this now: 351+x≥450.

Now we have to subtract 351 from both sides so we can find out what x is.

Our final answer is x≥99.

So the lowest score he can have to have at least a 90 is a 99.

I hope this helped :)

Answer 2

To have an average of At least 90 for 5 exams, the total points need to be at least ( 5 x 90) 450 points.

The total points he has for the 4 exams so far is: 94 + 73 + 89 + 95 = 351 points.

This means he needs at least a (450 - 351) 99 on the last exam.