Question

I usually use the Binomial probability table, but this time the online system want specific answer. Please help.

According to an​ airline, flights on a certain route are on time 80​% of the time. Suppose 20 flights are randomly selected and the number of on time flights is recorded. Use technology to find the probabilities.

The probability that at least 18 flights are on time is ______

Answer 1

:)

Answer 2

hi okay listen to me

Answer 3

listening @Hayhayz

Answer 4

kay listen to me

Answer 5

are you there

Answer 6

hey ?!?!

Answer 7

ill only help if u reply

Answer 8

@Hayhayz I'm here

Answer 9

kay listen to me maannn

Answer 10

u need to learn about that probability okay bro

Answer 11

okay...

Answer 12

lol

Answer 13

listen relax its easy, just rap with me

Answer 14

yo yo mojo yo yo froyo

Answer 15

im sorry, okay ill be serious!!

Answer 16

I know this is the formula. I tried it many times but this is my last attempt and I want to get it right. I would have not posted the question if I knew how to do it.

Answer 17

lets consider another example, similar to this, consider 4 dice, what is the chance 3 of them land on 1

Answer 18

im going to show u how all formulas come about

Answer 19

now focus, we have work to do

Answer 20

I know how they come and what probability is, i just thought the formula requires so many steps, I'm sure there is another way to do it.

Answer 21

the formula is shorrt and sweet

Answer 22

I have two tests tomorrow, it's whether you go straight to the point or thanks.

Answer 23

20 choose 2

Answer 24

k lets dothis then illl tell u solution

Answer 25

atleast 18 are on time to so, we want 18,19,20

Answer 26

yes, I usually use the given binomial table, but this time they want the formula answer. It may have more digits or something.

Answer 27

20 choose 2 * (80/100)^18*(20/100)^2
20 choose 1 * (80/100)^19*(20/100)^1
20 choose 0 * (80/100)^20*(20/100)^0

Answer 28

add em up

Answer 29

the binomial formula is the exact value of the prob

Answer 30

okay , I'll try that.

Answer 31

i thought u were doing that already

Answer 32

I did it and got .0151 , and I lost me last attempt, it was wrong. Maybe I did the math wrong. Thanks any way

Answer 33

you should have told me it was ur last attempt

Answer 34

http://www.wolframalpha.com/input/?i=190+*+(80%2F100)%5E18*(20%2F100)%5E2+%2B+20+*+(80%2F100)%5E19*(20%2F100)%5E1+%2B(80%2F100)%5E20*(20%2F100)%5E0

~20%

Answer 35

u little butt

Answer 36

http://www.wolframalpha.com/input/?i=(20+choose+2)*+(80%2F100)%5E18*(20%2F100)%5E2+%2B+20+*+(80%2F100)%5E19*(20%2F100)%5E1+%2B(80%2F100)%5E20*(20%2F100)%5E0