Question

Please help! Will give fan and medal.

When treated with antibiotic, 94% of all the dolphins are cured of an ear infection. if 7 dolphins are treated, find the probability that exactly 4 are cured.

Probability is ____.
Thank you in advance :)

Answer 1

i cuk at prob...x(

Answer 2

Oh, that's okay! Thanks anyway.

Answer 3

i can help

Answer 4

Okay! Yeh, that'd be great!

Answer 5

id say 0.134286

Answer 6

hold it did it wrong its actually 0.235

Answer 7

without the percent with dividing 94/4 its 23.5

Answer 8

might want to show your work @jjcoolja12

Answer 9

so i am guilty of being right

Answer 10

@inkyvoyd dude its just 94%/4 or 94/4

Answer 11

@Ray1998 , this is a binomial probability problem.

Answer 12

0.134286

Answer 13

without the percent its 13.428571

Answer 14

i've been proven guilty of being smart again

Answer 15

You are looking for the the probability that EXACTLY 4 dolphins are cured, right? let's look at it this way, C being cured and N being not cured... to get EXACTLY 4 dolphins cured, there are a lot of different ways.
Dolphin
1 2 3 4 5 6 7
CCCCNNN
CCCNCNN
CCCNNCN
CCNCCNN
...
precisely how many ways are there? Well, this is a combinatorics problem...
Let's think. We're trying to select 4 lucky dolphins from 7... does order matter?

Answer 16

What about the 7?

Answer 17

ok why do i have the feeling im wrong

Answer 18

Um, no?

Answer 19

so im not wrong eh probably in my other answered questions

Answer 20

So... do you know what you need to do to select 4 different dolphins from 7 dolphins? You said order doesn't matter.

Answer 21

No, I don't, sorry.

Answer 22

Do you recall permutations and combinations?

Answer 23

I don't think so, not from the top of my head.

Answer 24

You'll need them. take a quick look: http://www.mathwords.com/c/combination_formula.htm
should be familiar; let me know if you have any problems

Answer 25

Unfortunately I must leave; I did not get the lead in to explaining the formula to do this problem as I wished, but here is a link to what you need.

Answer 26

http://fsweb.bainbridge.edu/dbyrd/statistics/binomial.htm

Answer 27

you'll need the first link to apply the nCr formula so make sure you understand.
n will be 7, because you have 7 trials, and r will be 4, because you want 4 successes. p is .94 as the probaiblity of a dolphin getting cured is 94%, , so q will be 1-.94=0.06. Plug and chug.

Answer 28

7c4*(0.94)^4*(0.06)^3