Need help with probability questions

  • #1

Homework Statement



Q: Approximately 16% of the calls to an airline reservation phone line result in a reservation being made.

a. Suppose that an operator handles 15 calls. What is the probability that none of the 15 calls result in a reservation? (Give the answer to 3 decimals places.)

I have tried

1-.16=.84 (incorrcect)

I thought maybe it was not probable for an answer of 0 (incorrect)

I also at one point ended up with the answer 0.011 but cannot remember how I got that answer



b.What is the probability that at least one call results in a reservation being made? (Give the answer to 3 decimals places.)


I would think you would divide 1 by 15. Probable opportunities divided by actual opportunities. But, I am sure I am supposed to use the 16% in this equation somewhere....very stuck.

Homework Equations



I am new to this and this is my first math class in 25 years so I am not sure what to put here.


The Attempt at a Solution



for part a:
I have tried

1-.16=.84 (incorrcect)

I thought maybe it was not probable for an answer of 0 (incorrect)

I also at one point ended up with the answer 0.011 but cannot remember how I got that answer

for part b

I would think you would divide 1 by 15. Probable opportunities divided by actual opportunities. But, I am sure I am supposed to use the 16% in this equation somewhere....very stuck.
 

Answers and Replies

  • #2
UltrafastPED
Science Advisor
Gold Member
1,912
216
The calls are independent of each other, so each call has p=0.16 for creating a reservation.

Now you queue up the calls ...

A similar, perhaps easier to grasp, problem is the following:
1. each coin flip is p=0.50 heads
2. You flip the coin 15 times
3. What is the probability that none of the coin flips is heads?
 
  • #3
pbuk
Science Advisor
Gold Member
2,007
801
Did you manage to follow what was going on in class? Do have some notes or a handout from the class? Or a set book?

OK, I'll help you through this just this once :smile:

What percentage of the time does the first call not result in a reservation?
 
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