Hello!
Let's get important information in the exercise:
- mean height of 32 students = 1.515 metres
- mean height of 14 boys = 1.56 metres
First, we need to know the total height (sum all students height). So, we can multiply the number of students by the mean height:
[tex]\boxed{\mathrm{32\:students \cdot 1.515\:m = 48.48m}}[/tex]
Now, we need to know the total height of the boys, likewise:
[tex]\boxed{\mathrm{14\:boys \cdot 1.56m =21.84m }}[/tex]
At this moment, we also need to know the total height of the girls. It's simple, just subtract:
[tex]\boxed{\mathrm{48.48m - 21.84m = 26.64m}}[/tex]
Finally, calculating the mean height of the girls (just divide the total height by the number of girls):
[tex]\boxed{\mathrm{\dfrac{\:\:\:26.64m\:\:\:}{18\:girls}=1.48m}}[/tex]
So, the mean height of the girls equals 1.48.
Hope this helps! :)
