The Bureau of Labor Statistics publishes information on average annual expenditures by consumers in Consumer Expenditures. In

Question:

The Bureau of Labor Statistics publishes information on average annual expenditures by consumers in Consumer Expenditures. In 2007, the mean amount spent per consumer unit on nonalcoholic beverages was $333. A random sample of 12 consumer units yielded the following data, in dollars, on last year€™s expenditures on nonalcoholic beverages.

297 394 474 353 378 372 289 386 372 362 307 371

At the 5% significance level, do the data provide sufficient evidence to conclude that last year€™s mean amount spent by consumers on nonalcoholic beverages has increased from the 2007 mean of $333?

Use the Wilcoxon signed-rank test to perform the required hypothesis test.