Question

Naomi wants to earn an A (90%) in her math class. On her first three tests, she scored 87%, 98% and 86%. What score will she need to earn on her fourth test in order to have an average of 90%?

Answer 1

Naomi will need to score at least 89% on her fourth test to have an average of 90% in her math class.

Explanation:

To find out what score Naomi needs to earn on her fourth test in order to have an average of 90%, we can set up an equation.

Let's denote the score on the fourth test as "x". Naomi has taken three tests, and their scores are 87%, 98%, and 86%. To find the average, we sum up all the scores and divide by the number of tests:

(87 + 98 + 86 + x) / 4 = 90

Now we can solve for x:

(87 + 98 + 86 + x) = 4 * 90

271 + x = 360

x = 360 - 271

x = 89

Naomi will need to score at least 89% on her fourth test to have an average of 90% in her math class.