Question

If the mean of five observations \(x\), \(x + 2\), \(x + 4\), \(x + 6\), and \(x + 8\) is 11, then the value of \(x\) is:

• A. 5
• B. 6
• C. 7
• D. 8

Hint:

To calculate the mean of numbers in terms of variables, use the sum of the numbers and divide by the number of terms.

Answer 1

The Correct Option is C

The five observations are: \(x\), \(x + 2\), \(x + 4\), \(x + 6\), and \(x + 8\). The mean is given by: \[ \frac{x + (x + 2) + (x + 4) + (x + 6) + (x + 8)}{5} = 11. \] Simplify the equation: \[ \frac{5x + 20}{5} = 11. \] \[ x + 4 = 11. \] \[ x = 11 - 4 = 7. \] Thus, the correct answer is \( 7 \).