First, find the cost of 1 pepper.
Divide the cost given by the number of peppers:
2.25 / 5 = $0.45 per pepper
Now, multiply the cost per pepper (0.45) by the number of peppers asked in the table:
number of peppers : 1 2 3 4
Cost : 0.45 0.45x2 = 0.9 0.45x 3 = 1.35 1.8