Air pollution in large U.S. cities is monitored to see whether it conforms to requirements set by the Environmental Protection Agency. The following data, expressed as an air pollution index, give the air quality of a city for ?ve randomly selected days.
56.23 57.12 57.7 63.92 59.40
Construct a 99% jackknife con?dence interval for the actual variance of the air pollution index for this city and interpret.