The forecaster on tv said, "it's a scorcher! right now it's 90 degrees but the temperature will fluctuate at least 12 degrees by 3 pm. we'll tell you if we're getting hotter or colder in a minute! " what is the range of possible temperatures it could be at 3 pm

Temperature Right now = 90 degrees.

Temperature can either go above or below 90 degrees.The temperature can fluctuate atleast 12 degrees. 

This means temperature can fluctuate by a value of 12 or more than 12. 

12 degrees lesser than 90 is 78 and 12 degrees more than 90 is 102. 12 degrees is the minimum fluctuation

So, the range of possible temperatures at 3 pm can be listed as:

78 degrees or lesser OR 102 degrees or greater.