Thread: Probability Word Problem homework help

A group of students was recently polled about the technology they own.

69 own a cell phone
45 own a computer
23 own an ipod
4 do not own any of the above three items
34 own a cell phone but not a computer nor an ipod
6 own all three, a computer, an iPod, and a cell phone
8 own a cell phone and an ipod but not a computer
2 own only an ipod

a.) How many students were polled?

b.) What is the probability a randomly selected polled student owns a computer?

c.) What is the probability a computer owner also owns an iPod?

d.) What is the probability a randomly selected polled student owns an iPod or a cell phone?

e.) What is the probability a randomly selected polled student owns an ipod and a cell phone?

A Venn diagram will be very helpful to solve this. Have you tried drawing one?

I'll try

Once you do, post your answer to part a) and I will tell you if it agrees with what I got.

i got 89 for a.)

I got 45/89 for b.)

I get a different number for part a). Can you post your diagram?

edit: Did you leave out those who do not own any of the 3?

Yes so is 93?

Yes, that's what I have.

I got 13/93 for c
78/93 for d
8/93 for e

Is that what you got??

c) no

d) yes, but reduce the fraction.

e) no

C) 7/93
E) How is it not 8/93? It asks us the probability that a student owns an iPod and a cell phone, and the example tells us that 8 owns a cellphone and an ipod??????

c) No. You know there are 45 computer owners, so the denominator will be 45.

e) You are neglecting those who own all 3.

Right, but there are 6 others that have all three. They qualify don't they?

ok