Brrr…. Sure is cold outside. What is the difference between the temperature of our classroom and outside?

This site is a weather archive. You can use it to check today’s and previous day’s temperatures.

Suppose that the average classroom temperature has been 22 degrees Celsius for this week. Using the link provided, what is the sum of the difference between temps. for the past week? What is the mean difference for the week? How do you know?