We are looking for the price per oz. first for each cereal so $/oz.
$3.58/13= 0.275384615 round up to two decimal places so it is $0.28 per oz
$4.59/24 = 0.19125 round up to two decimal places so it is $0.19 per oz.
Then, we see that the 24oz. cereal is cheaper than the 13oz. because of the price per oz.