Given :
Temperature at first period , [tex]T_1=99^oF[/tex] .
Temperature at seventh period , [tex]T_7=102^oF[/tex] .
To Find :
The change in temperature .
Solution :
We know , change in temperature is given by the difference between final and initial temperature .
[tex]\Delta T=T_7-T_1\\\\\Delta=(102-99)^oF\\\\\Delta=3^oF[/tex]
So ,the change in temperature is [tex]3^oF[/tex] .
Now , the average body temperature of human body is [tex]98.6^oF[/tex] and [tex]100.4^oF[/tex] is considered a fever .
Therefore , we should not be in school and take rest .
Hence , this is the required solution .