Question

Please help me and give me an explanation

Answer 1

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:

`\boxed{\mathrm{32\:students \cdot 1.515\:m = 48.48m}}`

Now, we need to know the total height of the boys, likewise:

`\boxed{\mathrm{14\:boys \cdot 1.56m =21.84m }}`

At this moment, we also need to know the total height of the girls. It's simple, just subtract:

`\boxed{\mathrm{48.48m - 21.84m = 26.64m}}`

Finally, calculating the mean height of the girls (just divide the total height by the number of girls):

`\boxed{\mathrm{(\:\:\:26.64m\:\:\:)/(18\:girls)=1.48m}}`

So, the mean height of the girls equals 1.48.

Hope this helps! :)