Part 1.

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

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

Part 2.

A July 2011 Pew Research survey suggests that 27% of adults saythey regularly get news through Facebook, Twitter or other socialnetworking sites. What's the probability that in a random sample of10 people at most 1 of them get their news through socialnetworking sites?

A July 2011 Pew Research survey suggests that 27% of adults saythey regularly get news through Facebook, Twitter or other socialnetworking sites. What's the probability that in a random sample of10 people at most 1 of them get their news through socialnetworking sites?

• 0.20
• 0.96
• 0.16
• 0.04
• 0.06

Part 3.

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


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