We are given :
The ratio of orange juice to pineapple juice in tropical treat punch = 4:3 or 4/3.
Number of oz of orange juice = 64 oz.
Let us assume number of oz pineapple juice does he need = p.
We can setup an proportion:
64 : p = 4 : 3
On cross multiplication we get
64 × 3 = 4 × p
192 = 4p
Dividing both sides by 4, we get
p = 48.
<h3>Therefore, he needs 48 oz of pineapple juice.</h3>