The temperature reading that is halfway between −10 degrees and 40 degrees is ___ degrees. If the temperature was −3 degrees in the morning and 8 degrees in the afternoon, the change in temperature during that time is degrees.
If the temperature has been changing at a rate of −1.5 degrees each hour, and it is currently 5 degrees, the temperature 4 hours ago was ___ degrees.
If the temperature continues to change at this rate of −1.5 per hour, and it is currently 5 degrees, the temperature in 4 hours will be degrees.