Describe a pattern in the sequence 4, 6.5, 9, 11.5 & find the next two terms of the difference.

Each number in the sequence is 2.5 more than the previous number.

To describe the pattern in the given sequence, we need to observe the differences between consecutive terms. Let's calculate the differences:

6.5 - 4 = 2.5
9 - 6.5 = 2.5
11.5 - 9 = 2.5

We can see that the differences between consecutive terms are all 2.5. This suggests that the sequence is increasing by 2.5 each time.

Now, to find the next two terms of the difference, we need to continue this pattern.

11.5 + 2.5 = 14
14 + 2.5 = 16.5

The next two terms of the difference are 14 and 16.5.