Question

If the mean of the following set is 12, what is x?
(1,14,3,15,16,x,21,10)

Answer 1

To find what x is you must first make a solvable equation. You can take your knowledge of finding mean to do this

To find the mean of a set of data you must add the data together then divide the sum by the number of data in the set. You can make an equation from this and set it equal to 12 like so:

`(1+14+3+15+16+21+10+x)/(8) = 12`

First combine like terms:

`(80+x)/(8) = 12`

You can split up the fraction
`(80+x)/(8)` like so:

`(80)/(8) +(x)/(8)` = 12

Now you can simplify
`(80)/(8)` to 10

10 +
`(x)/(8)` = 12

Now bring 10 to the right side by subtracting 10 to both sides (what you do on one side you must do to the other). Since 10 is being added on the left side, subtraction (the opposite of addition) will cancel it out (make it zero) from the left side and bring it over to the right side.

10 - 10 +
`(x)/(8)` = 12 - 10

`(x)/(8)` = 2

Now we must completely isolate x. To do this you must multiply 8 to both sides. Since x is being divided by 8 you must multiply 8 to both sides to make 8 one on the left side and bring it over to the right side

`(x)/(8)` × 8 = 2 × 8

x = 16

Hope this helped!

~Just a girl in love with Shawn Mendes