Question

Im having trouble figuring this out too

Calculate the worst case uncertainty in P as follows: first calculate one extreme of P by using L=26 cm and W=16 cm. Then calculate the other extreme using L=24 cm and W=14 cm. The worst case spread is the difference in these two extreme values of P. Set this spread equal to 2 sigmaP and calculate sigmaP.

What i did so far

p1= 2(26) +2(14)=84 cm
p2= 2(26) +2(24)= 80 cm

84-80=4 cm

idk what to do from here
40 minutes ago - 4 days left to answer.
Additional Details
is it
2Sigmap= 4 cm

Sigmap= 2cm

?