Answer
Fried Chicken 32 pieces
Lasagna 11.2 pounds
Deli Meats 3.6 pounds
Sliced Cheese 1.87 pounds
Bakery Buns 2.4 dozen
Potato Salad 4.8 pounds
Work Step by Step
Fried Chicken $\frac{40\ pieces}{25\ people}\times20\ people$ = 32 pieces
Lasagna $\frac{14\ pounds}{25\ people}\times20\ people$ = 11.2 pounds
Deli Meats $\frac{4.5\ pounds}{25\ people}\times20\ people$ = 3.6 pounds
Sliced Cheese $\frac{2\frac{1}{3} pounds}{25\ people}\times20\ people$ = $\frac{\frac{7}{3} pounds}{25\ people}\times20\ people$ = $\frac{7}{3} pounds\times\frac{1}{25\ people}\times20\ people$ = $\frac{140}{75}\ pounds$ = 1.87 pounds
Bakery Buns $\frac{3\ dozen}{25\ people}\times20\ people$ = 2.4 dozen
Potato Salad $\frac{6\ pounds}{25\ people}\times20\ people$ = 4.8 pounds