Applications of Solving Equations

Contents

Problems

Problem : What is the mean average of {13, 15, 19, 13} ?

15

Problem : What is the mean average of {7, 12, 3, -2, -4, 14} ?

5

Problem : What is the mean average of {4, 13, 0, -12, -2, 21, -17} ?

1

Problem : What number must be added to the set {2, 6, 12, 0} to yield an average of 6?

10

Problem : What number must be added to the set {7, -7, 15} to yield an average of -5?

-35

Problem : Jonah receives the following scores on his biology tests: {95, 99, 92, 89} .
a) If 100 is the highest grade possible on a test, and there is one test left, what is the highest average Jonah can get?
b) What is the minimum score he needs on the final test to get an A (at least 90 average) in the class?

a) 95
b) 75

Problem : Kat receives the following scores on her chemistry tests: {88, 92, 74, x, 94, 85} .
a) If x = 80 , what is Kat's average?
b) If Kat's average is 83 , what is x ?
c) If the highest possible score on a test is 100 , can Kat get a 90 in the class?

a) 85.5
b) x = 65
c) No, she cannot get higher than an 88.8 (she would need a 107 on the fourth test to get a 90).