The temperature was originally at -23.3 if the instructions say that the temp rose 28.1 degrees, all you would have to do is add 28.1 on to -23.3.
a common misconception is that people will put down 28.1 as the answer, but that was the increase so you don't want to put that, you want to add that to the starting temperature.
Since the morning temp was -23.3 degrees and the temperature rose 28.1 degrees before reaching the high you do, -23.3+28.1 to get your answer of 4.8 Degrees F. Hope this helps! :)
