Question

Part 1.

About 24% of flights departing from New York's John F. Kennedy International Airport were delayed in 2009. Assuming that the chance of a flight being delayed has stayed constant at 24%, we are interested in finding the probability of 10 out of the next 100 departing flights being delayed. Noting that if one flight is delayed, the next flight is more likely to be delayed, which of the following statements is correct?

• We can use the geometric distribution with n = 100, k = 10, and p = 0.24 to calculate this probability.
• We cannot calculate this probability using the binomial distribution since whether or not one flight is delayed is not independent of another.
• We can use the binomial distribution with n = 100, k = 10, and p = 0.24 to calculate this probability.
• We can use the binomial distribution with n = 10, k = 100, and p = 0.24 to calculate this probability.

Part 2.

A July 2011 Pew Research survey suggests that 27% of adults say they regularly get news through Facebook, Twitter or other social networking sites. What's the probability that in a random sample of 10 people at most 1 of them get their news through social networking sites?

A July 2011 Pew Research survey suggests that 27% of adults say they regularly get news through Facebook, Twitter or other social networking sites. What's the probability that in a random sample of 10 people at most 1 of them get their news through social networking sites?

• 0.20
• 0.96
• 0.16
• 0.04
• 0.06

Part 3.

3.32 Arachnophobia: A 2005 Gallup Poll found that 7% of teenagers (ages 13 to 17) suffer from arachnophobia and are extremely afraid of spiders. At a summer camp there are 10 teenagers sleeping in each tent. Assume that these 10 teenagers are independent of each other.


(a) Calculate the probability that at least one of them suffers from arachnophobia.
(please round to four decimal places)
(b) Calculate the probability that exactly 2 of them suffer from arachnophobia?
(please round to four decimal places)
(c) Calculate the probability that at most 1 of them suffers from arachnophobia?
(please round to four decimal places)

Answer 1