A corporation owns a chain of several hundred gasoline stations on the eastern seaboard. The marketing director wants to test a proposed marketing campaign by running ads on some local television stations and determining whether gasoline sales at a sample of the company's stations increase after the advertising. The following data represent gasoline sales for a day before and a day after the advertising campaign. Use the Wilcoxon matched-pairs signed rank test to determine whether sales increased significantly after the advertising campaign. Let α = .05.

Assume the underlying distributions aresymmetrical.

Transcribed Image Text:

Station Before After $10,500 8,870 12,300 10,510 5,570 9,150 11,980 6,740 7,340 13,400 12,200 10,570 9,880 12,100 9,000 11,800 10,500 $12,600 10,660 11,890 14,630 8,580 10,115 14,350 6,900 8,890 16,540 11,300 13,330 9,990 14,050 9,500 12,450 13,450 4 10 12 13 14 15 16 17