Final answer:
The next number in the given arithmetic sequence is 88.
Step-by-step explanation:
The arithmetic sequence given in the question is: 123, 116, 109, 102, 95. To find the next number in the sequence, we need to determine the common difference. The common difference can be calculated by subtracting any two consecutive terms. In this case, we can subtract 109 from 116 to get a difference of -7. Therefore, the common difference is -7. To find the next term, we subtract the common difference from the last term in the sequence. So, 95 - 7 = 88. Therefore, the next number in the sequence is 88.