A better deal is the one which costs lesser. In order to compare the deals we need to bring them both to the same unit.
We have 24 ounce bag for 1.19$
So 1 ounce is 1.19/24 = 0.0496 $
Then we have 36 ounce for $2.89
So 1 ounce is 2.89/36 =.0803 $
Comparing the two the deal for 24 ounces for 1.19$ is cheaper and hence better.
To compare for similar units, we can look at the LCM. LCM of 24 and 36 is 12.
for the first one 12 ounces cost 1.19/2 $ =.595
For the second 12 ounces cost 2.89/3 $ =.763
Again, the first deal is cheaper and hence better