Lucy has taken four tests in math class and has an average of 85. i. What score would she have to get on her fifth test to have an average of 88? ii. Can she get an average of 90? Explain. i. She would need a perfect score of 100 from our Missing Average Calculator ii. Impossible since we know from question i., a score of 100 only gets her to an 88. She cannot score higher than 100 on the fifth test, therefore, she cannot attain an average score of 90.