SOLUTION: Help please - I have tried to use the Binominal Distribution formula to solve this question but I think the wording is confusing me and I am using the wrong values. Maybe I need t

Algebra ->  Probability-and-statistics -> SOLUTION: Help please - I have tried to use the Binominal Distribution formula to solve this question but I think the wording is confusing me and I am using the wrong values. Maybe I need t      Log On


   

Question 877978: Help please - I have tried to use the Binominal Distribution formula to solve this question but I think the wording is confusing me and I am using the wrong values. Maybe I need to use the Hypergeometric or Poisson - very confused.

Here is the question: A company reserved 20 rooms for a training class at a hotel that advertised "99% of our guests are delighted with their stay!" Surveys showed that 2 of the attendees were dissatisfied with the hotel. What is the probability that 2 or more guests would be dissatisfied if the hotel's advertising claim was true?
Thank-you kindly
Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!
Yes, that's a binomial problem.  The probability that there are 19 or
fewer successes out of 20 trials, where the probability of success in ONE
trial is .99

n = 20 trials
p = .01 = probability of 1 "success" in 1 trial.

Note: Here a "success" is that a person would be satisfied.

x <= 19

With my TI-84

Press ON
Press CLEAR
Press 2ND
Press VARS
Use down arrow key to scroll to B:binomcdf(
Press ENTER

Depending on how old your calculator is or what mode it is in,
you may see this:

                         binomcdf
                      trials:
                      p:
                      x value
                      Paste

If so make it read      binomcdf
                      trials:20
                      p:.99
                      x value:19
                      Paste

Highlight Paste
Press ENTER

You'll see:  

binomcdf(20,.99,
19)

Or if you have an old TI-84 see binomcdf(
Make it read 

binomcdf(20,.99,
19)

Press ENTER   

You'll see .0010035762

Edwin