Question

4. Your test scores for the semester are 87, 84, and 85. Can you raise your test average to 90with your next test?Define:Equation:Answer:

Answer 1

In order to find the value of your next test, to acquire an average value of 90 points taking into account the previous scores, you use the following formula for the average value of a set of numbers:

`(87+84+85+x)/(4)>90`

The previous inequlity stablishes that for the next test, with unknown score x, you will get an average higher than 90.

You solve the previous inequality:

`\begin{gathered} (87+84+85+x)/(4)>90 \\ (256+x)/(4)>90 \\ 256+x>4(90) \\ x>4(90)-256 \\ x>360-256 \\ x>104 \end{gathered}`

Hence, you need to get 104 scores in your next test, in order to obtain an average higher than 90 scores in the semester.