编辑值后，平均功能不返回正确的输出

I am new to AngularJS, and I have a slight problem. I have a list of cities that I would like to compute the average temperature, and for some reason, after editing the temperature values in the list of cities, the function to compute the average temperature is returning incorrect values. It returns the correct value after loading the page, but after editing the temperature values I get incorrect results.I am new to AngularJS, and I have a slight prob