【Question 5】A class has 30 students, the average height of the students is 140 cm, among them, there are 18 boys, and the average height of the boys is 144 cm, then the average height of the girls is $\qquad$ cm.
Analysis:
(Solution 1)
Number of girls $30-18=12$ (people)
Average height of girls is $140-(144-140) \times 18 \div 12=134(\mathrm{~cm})$
(Solution 2)
Number of girls $30-18=12$ (people)
$$
(140 \times 30-144 \times 18) \div 12=134(\mathrm{~cm})
$$