The Department of Service Financing in the city of Belmont, New York, has been experimenting with having city units provide services in-house versus having private contractors provide the same services. In the city's ground department, half of the landscaping work is performed by city crews, whereas the other half is performed by a private landscaping firm. The city manager has collected random samples of weekly expense report data for both providers. She asks you to conduct a difference of means test. What can the city manager conclude about the difference between in-house and private-service provision