Calculate Average Change: Removing 11 from Sequence {1,2,3,11}

To solve this problem, we need to follow these steps:

• Step 1: Determine the average of the initial set of numbers $(1, 2, 3, 11)$.
• Step 2: Determine the average of the set after removing 11 $(1, 2, 3)$.
• Step 3: Compare the averages to see the change—the average should be noted as decreasing or increasing or remaining the same.

Step 1: Calculate the average of the initial set $(1, 2, 3, 11)$:

The sum of these numbers is $1 + 2 + 3 + 11 = 17$.
There are 4 numbers in this set.
Thus, the average is $\frac{17}{4} = 4.25$.

Step 2: Calculate the average of the new set $(1, 2, 3)$:

The sum of these numbers is $1 + 2 + 3 = 6$.
There are 3 numbers in this set.
Thus, the average is $\frac{6}{3} = 2$.

Step 3: Compare the two averages:

The original average was $4.25$, and the new average is $2$. The average has decreased from $4.25$ to $2$.

Therefore, the solution to the problem is: It will decrease.