Question

Researchers in the corporate office of an airline wonder if there is a significant difference between the cost of a flight on Priceline.com vs. the airline's own website. A random sample of 15 flights were tracked on Priceline and the airline's website and the 90% confidence interval for the mean difference in price (Priceline - Airline Site) was (-64.52, 32.5). Which of the following is the appropriate conclusion?

Question 3 options:

1)	There is no significant difference between the average price for the booking options

2)	We are 90% confident that the average difference in price is positive, with the higher price coming from Priceline.

3)	We are 90% confident that the average difference in price is positive, with the higher price coming from the Airline sites

4)	We are 90% confident that the average difference in price is negative, with the higher price coming from the Airline sites

5)	We are 90% confident that the average difference in price is negative, with the higher price coming from Priceline.

Question 4 (1 point)

Automobile manufacturers are interested in the difference in reaction times for drivers reacting to traditional incandescent lights and to LED lights. A sample of 30 drivers are told to press a button as soon as they see a light flash in front of them and the reaction time was measured in milliseconds. Each driver was shown each type of light. The average difference in reaction times (traditional - LED) is -2.7 ms with a standard deviation of 7.23 ms. A 90% confidence interval for the average difference between the two reaction times was (-4.94, -0.46). Which of the following is the best interpretation?

Question 4 options:

1)	We are 90% confident that the average difference in reaction time between the two light types for all drivers is between -4.94 and -0.46.

2)	We are 90% confident that the difference between the average reaction time for LED lights and the average reaction time for traditional lights is between -4.94 and -0.46.

3)	The proportion of all drivers that had a difference in reaction times between the two lights is 90%.

4)	We are 90% confident that the average difference in the reaction times of the drivers sampled is between -4.94 and -0.46.

5)	We are certain the average difference in reaction times between the two light types for all drivers is between -4.94 and -0.46.

Answer 1

Q.1) Given that, the 90% confidence interval for the mean difference in price (Priceline - Airline Site) was (-64.52, 32.5).

Interpretation: We are 90% confident that the average difference in price is negative, with the higher price coming from the Airline sites.

Q.2) Given that, a 90% confidence interval for the average difference between the two reaction times was (-4.94, -0.46).

Interpretation: We are 90% confident that the average difference in reaction time between the two light types for all drivers is between -4.94 and -0.46.