Question

probability question
P (8th-grade boy) see attachment

Answer 1

you can use the table to answer questions, but you need the question.
For example, if all 50 are in one room and you randomly pick one, what is the chance its a 7th grader?
the table says there are 13 kids in the 7th grade, so the chances would be 13/50

Answer 2

i was confused on which total i needed the total for all boys or total of 8th graders

Answer 3

If the question, what is the probability of choosing an 8th grade boy out of all 50 kids, the answer is 10/50 = 1/5

Answer 4

it didnt say out of which set i needed to pick from

Answer 5

@phi i posted a screenshot of the question

Answer 6

They are not explicit (or, as the saying goes... "it goes without saying") they mean the probability of picking e.g. a 7th grade girl out of all attendees at the camp.

Answer 7

oh ok so i need to use the total of all 8th graders then?

Answer 8

Unless told otherwise, I would use 50 (the entire number of kids) in the denominator.

Answer 9

in probability, it is the ratio of "# of cases that match" divided by total possible

the total possible (the universe) is everything. In this case, all 50 kids, according to your table.

Answer 10

oh ok thanks @phi