After 5 tests, her average was 88. To have a seven-test average of 90, the total must be:
[tex] 90 \times 7 = 630 [/tex]
Her average after 5 tests was 88. Her total score on the 5 tests is:
[tex] 88 \times 5 = 440 [/tex]
Subtract:
[tex] 630-440 = 190 [/tex]
Find the average by dividing by 2:
[tex] 190 \div 2 = 95 [/tex]
Her average must be 95
