3 x 500
+
3 x 80
+
3 x 4
=
1,752
By expanding 584 and multiplying the different parts by 3, the multiplying is simplified. Then you just have to add together the multiplication you did.
2πrh= S
π = S/(2rh)
the answer to the question
When Oliver is considering the number of males, he typically assigns people to two categories: make or female, which makes the variable bi-variate : with two values.("bi" means "two).
If he's more inclusive, and adds the category of "other", it would be a categorical data - with 3 categories.