To determine the rule for generating the next term in the sequence 23, 19.5, 16, 12.5, let's examine the differences between successive terms:
- From 23 to 19.5, the difference is \( 19.5 - 23 = -3.5 \)
- From 19.5 to 16, the difference is \( 16 - 19.5 = -3.5 \)
- From 16 to 12.5, the difference is \( 12.5 - 16 = -3.5 \)
Since each term is generated by adding a common difference of -3.5 to the previous term, the correct statement is:
Add the common difference of -3.5.