Purse Snatching. The Federal Bureau of Investigation (FBI) compiles information on robbery and property crimes by type and selected characteristic and publishes its findings in Uniform Crime Reports....

Purse Snatching.
The Federal Bureau of Investigation (FBI) compiles information on robbery and property crimes by type and selected characteristic and publishes its findings in Uniform Crime Reports. According to that document, the mean value lost to purse snatching was $468 in 2012. For last year, 12 randomly selected purse-snatching offenses yielded the
following values lost, to the nearest dollar.

Use a t-test to decide, at the 5% significance level, whether last year’s mean value lost to purse snatching has decreased from the 2012 mean. The mean and standard deviation of the data are $455.0 and $86.8, respectively.