Final answer:
The second largest number in a sequence of four consecutive numbers that add up to 66 is 18.
Step-by-step explanation:
The question asks us to find the second largest number in a sequence of four consecutive numbers whose sum equals 66. To solve this, first, we determine the average of the four numbers (66 divided by 4 equals 16.5), which means the numbers are around this average. Since we are looking for whole numbers, the sequence of four consecutive numbers will be 16, 17, 18, and 19 which add up to 66. Therefore, the second largest number is 18.