Answer: He can predict that 420 students will be in support of the purchase.
Step-by-step explanation:
Since Randy surveyed one student out of every 5 he came across in the cafeteria, it means that if he came across five people, he will survey one, if he came across ten students, he will survey 2 and so on.
If then he surveyed a total of 140 students, then we can actually multiply the number by 5 to know the exact number of students he possibly came across in the cafeteria:
= 140 × 5
= Total of 700 students
If 84 out of the surveyed students supported the purchase, we can find what that figure represents in the total number of students in the cafeteria:
84/140 = x/700
We cross multiply
140 × X = 84 × 700
140X = 58,800
X = 58,800/140
X = 420 students
Therefore, he can predict that 420 students out of a total of 700 students in the cafeteria will be in support of the purchase of the P.E equipment