Math problem


#1

I should know how to do this, but I get confused every time. This is Statistics by the way.

Basically, you are trying to get in contact with somebody in California. 68% of the houses have unlisted number. You sample 150 households.
What is the probability that between 50 and 65 (including 50 and 65) households have listed numbers?


#2

im in 8th grad and havn’t done statistics yet, buuuuut if i did it right then it’s 68%. hope it works ;D


(JayVee) #3

I think that it’s 0%. If 68% have an unlisted number, then that means 32% of them have a listed number. Multiply that to 150, then you get 48, which is less than 50.

That’s my guess, but don’t take my word for it. This is beyond my mathematical abilities :stuck_out_tongue:


#4

oops, i got the unlisted houses :stuck_out_tongue:
ok, this is how i did it

65-50=15 cause that’s the only #'s that matter

100%-68%=32%

15x 32%=4.8

4.8/15= .32% chance of a listed house.

And P.S. what grade is this?


#5

But there are 16 houses.
House 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 90, 61, 62, 63, 64, 65.


#6

Yeah, ijuggleyoyos. No offense but you have absolutely no idea what you’re doing.

Catorameus has gotten the closest but I don’t think he’s right.

EDIT: Messed around a bit with the numbers and I think I got it right. 0.3960 Anyone else got this?


#7

ya, i don’t. but i solved it the most logical way to me :stuck_out_tongue:


(JM) #8

Looking at the numbers, that answer is logical and definitely within the ballpark.


(Marvin.D) #9

i have problem for yall

7 girls get on a bus,each girl has 7 kittens in her bookbag,and ever kitten,has 1 mother cat. how many legs are there in all?


(Runez4lyf) #10

I think it is 406 legs…
14 individual cats in a bag times 4 because they have 4 legs.
(56)
Times 7 for seven kids.
(392)
Plus 14 because of each girl’s legs…
(406)

There you go!


(Marvin.D) #11

nope think again


(Raphael) #12

who keeps a kitten in a bookbag? and the Is the mother cat with the kittens?


#13

Too many. Lol.

It’s 14x7=98 kittens x 4 legs per=392+7girlsx2 legs per=392+14=406…how is that not right?

Way to hijack my thread by the way. :stuck_out_tongue:

EDIT: Got another one. I got an answer but I don’t know if I did it right.
Basically: A construction worker pulls a 16 ft plank up the side of a building with a rope. He pulls it up at .5ft/s, and the bottom end up the plank follows a path perpendicular to the building. How fast is the end of the plank sliding along the ground when it is 8 ft from the wall of the building?
http://img10.imageshack.us/img10/1230/88618576.png
That’s more or less the image it gives. I got .87 ft./sec but I don’t know if that’s right.


(Raphael) #14

You forgot the driver ::slight_smile:

what you did seems right though 10 10010 1001 1 1110 (Brian is so much easier)


#15

Oh facepalm That was pretty good.

I think we’re going over the homework anyways so I’ll be fine.


(Marvin.D) #16

each cat has one mother cant now do the math


(Jesse) #17

Wait, isn’t it 138 legs?


#18

98 kittens and/or cats. Whatever. The answer is 408 because of the driver of the bus.

Where’d 138 come from?


(Jesse) #19

Nevermind, I did the mother cat part wrong, it’s 406. They never said there was a driver, they’re just randomly getting onto a bus. If there was a driver, he or she would have been mentioned in the riddle, plus, it would be 410 because we all know bus drivers walk on all fours.


#20

Lol. But that’s the part of many riddles.

You are driving a bus with 18 people on it. If 18 people get off, who is left?

Kind of the same idea.