Answer: 123.5 centimeters
Step-by-step explanation:
Let sum of observations be S and number of observations be n.
Average A=[tex]\frac{\text{S}}{\text{n}}[/tex]
The average height of 4 children is (15h-3)
[tex](15h-3)=\frac{S}{4}\\\Rightarrow\ S=4(15h-3)\\\Rightarrow\ S=60h-45[/tex]
Also, when two more children join the group with heights of (10h+46) centimeters and (14h-16) centimeters the sum of heights of 6 children will be
[tex]S+(10h+46)+(14h-16)=60h-45+10h+46+14h-16=84h-107[/tex]
Now, Average height of 6 students=[tex]\frac{84h-15}{6}[/tex]
At h=9
Average height of 6 students=[tex]\frac{84(9)-15}{6}=\frac{741}{6}=123.5\ centimeters[/tex]