If the probability of hearing a "yes" to a campaign contribution drive is 0.07, and 250 requests are made, what is the probability of getting at least 20 positive responses?

Question

ybarrap · Answer

How are you thinking about solving this problem?

anonymous · Answer

honestly, I have no clue...

ybarrap · Answer

Have you heard about the Binomial Distribution? https://en.wikipedia.org/wiki/Binomial_distribution You will need this

anonymous · Answer

Okay, I think I got this now... kinda

ybarrap · Answer

Ok. Tell me.

ybarrap · Answer

Just tell me in a sentence, don't worry about the math

anonymous · Answer

Sentences in math, oi... its actually easy for write out the equation instead...Not quite sure about this but here is what I got
(250/20)*(0.07)^20*(0.93^231)=0.846
Am I right or wrong?

ybarrap · Answer

You've got the flavor of it. 

We need to count all the ways of having more than 20 people out of 250. This is hard. Let's do something easier, let's count the number of ways to have LESS than 20 people.

That's easier. 

That's our strategy.l In a sentence (or two).

ybarrap · Answer

Once we have the probability of less or equal  20, we will subtract this from 1 to get the probability of greater than 20.

anonymous · Answer

Okay, let me try working something else out real quick

anonymous · Answer

I checked with my teacher and she helped me work the problem but thanks for the help, you got me started so i could finish.

ybarrap · Answer

You're welcome