Answer: 10.95
Explanation:
To identify the pattern, we need to look at the differences between the given numbers.
The difference between 10.21 and 9.47 is 0.74.
The difference between 10.57 and 10.21 is 0.36.
The difference between 12.15 and 10.57 is 1.58.
We can see that the differences between the numbers are not constant. However, the differences themselves follow a pattern: they are increasing by 0.38 each time.
So, to find the missing number, we can add 0.38 to 10.57:
10.57 + 0.38 = 10.95
Therefore, the missing number is 10.95.