Mean

To find the value of , we start by using the formula for the mean of a set of observations. The mean of the 5 observations is given as 11.
Step 1: First, write down the expression for the sum of the observations:

Step 2: Simplify the sum:

Step 3: Use the formula for the mean, which is the sum of observations divided by the number of observations:

Step 4: Solve the equation for :

Multiply both sides by 5:

Step 5: Subtract 20 from both sides:

Step 6: Divide both sides by 5:

Thus, the value of is 7.