Question

1. An American based commuter airline has taken a survey of its 15 terminals and has obtained the following data for the month of February, where

Sales       = Total revenue based on number of tickets sold ($’000)

Promote = Amount spent on promoting the airline in the area ($’000)

Comp     = Number of competing airlines at the terminal

Free       = The percentage of passengers who flew free (for various reasons)

Use the additional following table to answer part a.

SALES ($'000)	PROMOTE ($'000)	COMP	FREE
79.3	2.5	10	3
200.1	5.5	8	6
163.2	6	12	9
200.1	7.9	7	16
146.0	5.2	8	15
177.7	7.6	12	9
30.9	2.0	12	8
291.9	9.0	5	10
160.0	4.0	8	4
339.4	9.6	5	16
159.6	5.5	11	7
86.3	3.0	12	6
237.5	6.0	6	10
107.2	5.0	10	4
155.0	3.5	10	4

  

1. For an upcoming new terminal, the airline intends to spend $6,500 on promotion, expects 7 competitors, and expects 11% of the passengers to fly free. Develop a 95% confidence interval for the mean value of the dependent variable sales. Also, develop a 95% prediction interval for the individual value of the dependent variable sales.

Answer 1

Minitab > Stat > Regression > Regression > Fit regression model

For CI and PI

After regression output, again stat > regression > regression > Predict

The airline intends to spend $6,500 on promotion, expects 7 competitors, and expects 11% of the passengers to fly free

After submitting value in equation,

Sales = 214.899 or 214.9

95% CI = (194.014, 235.785)

95% PI = (151.111, 278.687)

Answer 2

Minitab > Stat > Regression > Regression > Fit regression model

For CI and PI

After regression output, again stat > regression > regression > Predict

The airline intends to spend $6,500 on promotion, expects 7 competitors, and expects 11% of the passengers to fly free

After submitting value in equation,

Sales = 214.899 or 214.9

95% CI = (194.014, 235.785)

95% PI = (151.111, 278.687)