Respuesta :
average of 4 tests is 85
last test is x the one he needs
[tex] \frac{88+92+76+x}{4}=85 [/tex]
times 4 both sides
88+92+76+x=340
256+x=340
minus 256 from both sides
x=84
he has to get 84
he should use[tex] \frac{88+92+76+x}{4}=85 [/tex]
last test is x the one he needs
[tex] \frac{88+92+76+x}{4}=85 [/tex]
times 4 both sides
88+92+76+x=340
256+x=340
minus 256 from both sides
x=84
he has to get 84
he should use[tex] \frac{88+92+76+x}{4}=85 [/tex]
Answer: The student need to get 84 marks in the fourth test to have an average of 85 for all four tests
Step-by-step explanation:
Since we have given that
Scores of a student were
88, 92, 76 on three math tests.
Since we want an average of 85 for all four tests.
Let the score he get on fourth test of Math be x.
As we know the formula for " Average" :
[tex]Average=\frac{\text{ Sum of all observation }}{\text{ Total number of observation }}\\\\85=\frac{88+92+76+x}{4}\\\\85\times 4=88+92+76+x\\\\340=256+x\\\\340-256=x\\\\84=x[/tex]
Hence, The student need to get 84 marks in the fourth test to have an average of 85 for all four tests.