Question

So far this quarter your science quiz scores are: 89 95 85 83 88. You have one more science quiz to take. What do you need to get to make sure you end up with at least a 90% average

Answer 1

Answer:

$100\:[\%]$

Step-by-step explanation:

The average of a set of $n$ values is equal to the sum of the values in the set divide by $n$.

After you take another quiz, you'll have a total of six scores. Therefore, to end up with an average of 90, the sum of all your scores must be at least $6\cdot 90=540$

Therefore, we can set up the following inequality:

$89+95+85+83+88+n\geq540,\\440+n\geq 540,\\n\geq \boxed{100}$

Therefore, the minimum score you need to get to end up with a 90% average is $\boxed{100\:\%}$.