Answer:
To find out what score Sarah needs on her next test to achieve an average of 88, we can set up an equation. Let x represent the score she needs on the fifth test:
(80 + 95 + 75 + 90 + x) / 5 = 88
Now, let's solve for x:
(340 + x) / 5 = 88
To isolate x, first multiply both sides of the equation by 5:
340 + x = 440
Now, subtract 340 from both sides to find x:
x = 440 - 340
x = 100
Sarah needs to score 100 on her next test to achieve an average of 88.