In the past, patrons of a cinema complex have spent an average of $2.50 for popcorn and other snacks, with a standard deviation of $0.90. The amounts of these expenditures have been normally distributed.
Following an intensive publicity campaign by a local medical society, the mean expenditure for a sample of 18 patrons is found to be $2.10.
In a one-tail test at the 0.05 level of significance, does this recent experience suggest a decline in spending? Determine and interpret the p-value for the test.