Multiple choice

If the mean of observations $x, x + 2, x + 4, x + 6$ and $x + 8$ is $11$, find the value of $x$:

  1. $8$
  2. $5$
  3. $6$
  4. $7$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Mean = (x + x+2 + x+4 + x+6 + x+8) / 5 = 11. (5x + 20) / 5 = 11. x + 4 = 11. x = 7.

AI explanation

The formula for the arithmetic mean of observations is the sum of the observations divided by the total number of observations. Adding the terms gives 5 times x plus 20, and dividing by 5 observations gives a mean of x plus 4. Setting this equal to 11 gives the equation x plus 4 equals 11. Solving for x by subtracting 4 from 11 results in x equal to 7.

Keep practicing — related questions