Airport securityThe Transportation Security Administration (TSA) is responsible for airport safety. On some flights, TSA officers randomly select passengers for an extra security check prior to boarding. One such flight had 76passengers—12in first class and 64in coach class. Some passengers were surprised when none of the 10passengers chosen for screening were seated in first class. We want to perform a simulation to estimate the probability that no first-class passengers would be chosen in a truly random selection.

a. Describe how you would use a table of random digits to carry out this simulation.

b. Perform one trial of the simulation using the random digits that follow. Copy the digits onto your paper and mark directly on or above them so that someone can follow what you did.

c. In 15of the 100trials of the simulation, none of the 10passengers chosen was seated in first class. Does this result provide convincing evidence that the TSA officers did not carry out a truly random selection? Explain your answer.

Short Answer

Expert verified

a. We assign a unique number from 13to 76to each passengers in the coach class.

Now, we choose a row from the random digits table. Then we select the first two-digit number. If the number is between 01and 76then select the corresponding passenger

b. The first two-digit number is then chosen. Select the corresponding passenger if the number is between 01and 76, otherwise ignore the number and choose the next two-digit number. We'll do it again until you've chosen ten different passengers

c. Numerous trials resulted in no first-class passengers, it is likely that no first-class passengers will be selected, and thus there is no conclusive proof that the TSA officers did not select passengers at random.

Step by step solution

01

Part (a) Step 1 : Given Information

We have to describe how you would use a table of random digits to carry out this simulation.

02

Part (a) Step 2 : Simplification

In the question the TSA wants to check the security of the passengers by taking out the random sample. We need to describe how we would use a table of random digits to carry out this simulation. Thus, we have 76passengers: 12in first class and 64in coach class. And 10of the 76passengers are chosen for screening. Then we assign a unique number from 1to 12to each passengers in first class and we assign a unique number from 13to 76to each passengers in the coach class.

Now, we choose a row from the random digits table. Then we select the first two-digit number. If the number is between 01and 76then select the corresponding passenger, else ignore the number and select the next two-digit number. We will repeat it until you have selected ten unique passengers.

03

Part (b) Step 1 : Given Information

We have to perform one trial of the simulation using the random digits given.

04

Part (b) Step 2 : Simplification

The TSA intends to assess the security of the passengers by taking a random sample in the query.
As a result, there are 76passengers, including 12in first class and 64in coach. And 10of the 76passengers are chosen for screening out of a total of 76. Then, for each passenger in first class, we assign a unique number ranging from 1to 12, and for each passenger in coach class, we assign a unique number ranging from13 to 76.

71487,09984,29077,14863,61683,47052,62224,51025

The first two-digit number is then chosen. Select the corresponding passenger if the number is between 1and 76, otherwise ignore the number and choose the next two-digit number. We'll do it again until you've chosen ten different passengers. as an example,

71⇒ Select passenger71

48⇒ Select passenger 48

70⇒ Select passenger70

99⇒ Ignore

84⇒ Ignore

29⇒ Select passenger 29

07⇒ Select passenger07

71⇒ Ignore

48⇒ Ignore

63⇒ Select passenger 63

61⇒ Select passenger61

68⇒ Select passenger 68

34⇒ Select passenger34

70⇒ Ignore

52⇒ Select passenger52

We then note that the sample contains passengers 71,48,70,29,07,63,61,68,34,52while only passenger 07 is a first class passenger.

05

Part (c) Step 1 : Given Information

We have to explain if in 15 of the100 trials of the simulation, none of the ten passengers chosen was seated in the first class does this result provide convincing evidence that the TSA officers did not carry out a truly random selection.

06

Part (c) Step 2 : Simplification

The TSA intends to assess the security of the passengers by taking a random sample in the query. Now, none of the ten passengers picked for the simulation were seated in first class in 15of the100 trials. Because numerous trials resulted in no first-class passengers, it is likely that no first-class passengers will be selected, and thus there is no conclusive proof that the TSA officers did not select passengers at random.

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