Question

Alexis recieved an 85,89,92on three tests.How many points does she need to score on her next test in order to have an average of at least 90?

Answer 1

94

(85+89+92+x)/4 = 90

(266+x)/4 = 90
(Multiply by 4 on each side to get rid of it)

266+x=360
(subtract 266 from each side)

x = 94

Answer 2

94

Explanation:

Given: Alexis recieved an 85,89,92on three tests

To Find: Number of points she needs to score in order to have an average of atleast 90.

Solution:

Let the marks scored by Alexis in next test =
`\text{x}`

Marks scored by Alexis in three test =
`85`

`89`

`92`

Sum of marks scored by Alexis =
`85+89+92`

=
`266`

Average of Alexis's marks after next test =
`\frac{\text{Sum of marks of all tests}}{4}`

=
`\frac{266+\text{x}}{4}`

To have average of at least 90

`\frac{266+\text{x}}{4}`≥90

`266+\text{x}\geq 360`

`\text{x}\geq 94`

Alexis needs to score atleast 94 to have an average of at least 90