It is given in the question that cost of pork is $7.99/kg.
It means cost of 1 kg pork is $7.99.
Cost of 2 kg of pork is
[tex] =2*7.99 = $15.98 [/tex]
And cost of 3 kg of pork is
[tex] = $7.99*3 = $23.97 [/tex]
Therefore cost of 3.5 kg of pork is
[tex] = 3.5*7.99 = $27.965 [/tex]