9. (6 points) The Red Scarf Spring Festival Consolation Group encountered the following problem when determining the performance program for the nursing home: On New Year's Eve, there are 4 performances: singing, dancing, acrobatics, and skit. If singing is not to be scheduled as the 4th item, dancing is not to be scheduled as the 3rd item, acrobatics is not to be scheduled as the 2nd item, and the skit is not to be scheduled as the 1st item. Then, the number of different arrangements that meet the above requirements is $\qquad$.
【Solution】Solution: $3 \times 3 \times 1 \times 1=9$ (ways) $1234,1432,1243,2413,2134,2143,3142,3214,3412$, a total of 9 ways. Answer: There are 9 different ways to arrange the program list that meets the above requirements. Therefore, the answer is: 9.