Question

R 3. The mean of 4 numbers is 8. Three of the numbers add up to 22. What is the last number?​

Answer 1

let the last number be x

we know,

`\boxed{mean = (sum \: \: of \: \: all \: \: observations)/(number \: \: of \: \: observations) }`

So,

`\hookrightarrow \: 8 = (22 + x)/(4)`

`\hookrightarrow \: 8 * 4 = 22 + x`

`\hookrightarrow \: 32 = 22 + x`

`\hookrightarrow \: x = 32 - 22`

`\hookrightarrow \: x = 10`

therefore, the last number is 10.