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4 votes
Teresa has scored 70 , 60 , and 71 on her previous three tests. What score does she need on her next test so that her average (mean) is 70? Could someone answer it with the explanation please?

1 Answer

4 votes
(70+60+71+x)/4=70
Multiply 4 on both sides
201 + x = 280
Subtract 201 from both sides
x= 79
User Bao Le
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