Binomial and Poisson Distribution

Bob is taking a 100 question test.  They have a 90 % probability of getting any one question correct.  WHICH IS THE CORRECT FORMULA TO FIND OUT THE PROBABILITY that they will answer EXACTLY 70  questions correctly?

• ₁₀₀C₇₀   ( 0.18  )³⁰ ( 0.90  )⁷⁰
  

• ₁₀₀C₇₀   ( 0.10  )³⁰ ( 0.90  )⁶⁰

• ₁₀₀C₇₀   ( 0.10  )³⁰ ( 0.90  )⁷⁰

• ₉₉C₇₀   ( 0.10  )³⁰ ( 0.90  )⁷⁰

Find the mean of a binomial distribution with n=50 and p=0.4

• 50

• 4

• 20

• 10

Find the standard deviation of a binomial distribution with n=50 and p=0.4 (Round to the nearest tenth)

• 4.2

• 3.5

• 12.0

• 6.2

At a certain restaurant, there is a 70% probability that the flowers on your table will be yellow. If you are there with a group that is occupying 6 tables, what is the probability that 5 of the tables will have yellow flowers?

• 70%

• 70.6 %

• 30.3 %

• 5.0 %

Poisson Formula: P(X=x)

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• 
• 
• 

Assuming that breakdowns in electricity supply occur ramdomly with mean of one breakdown every 10 weeks. Find the probability of at least 2 breakdowns in any period of one week

• 0.0047

• 0.0952

• 0.0002

• 1.000

The mean number of accidents per month at a certain intersection is 3.What is the probability that in any given month exactly 4 accidents will occur at this intersection?

• 0.081

• 0.672

• 0.168

Find the variance of a binomial distribution with 50 trials and p= 0.4

• 12

• 15

• 10

• 20

• True

• False

Is the following Poisson or binomial distribution:

In the old days, there was a probability of 0.8 of success in any attempt to make a telephone call.

• Poisson

• Binomial

• Neither