Answer:
(a)The cost of per ounce of yogurt = $0.45
(b) The the cost of Reid's bowl = $3.51
Explanation:
Here, according to the question :
The cost of 9.2 ounce yogurt bowl = $4 .14
The cost of 8.1 ounce yogurt bowl = $3.65
(a) Now,

=

So, the cost of per ounce of yogurt = $0.45
(b) Now, the amount if yogurt in Reid's Bowl = 7.8 ounces
So, the total cost of her bowl with 7.8 ounce yogurt = 7.8 x ( cost of 1 ounce of yogurt)
= 7.8 x ( $0.45) = $3.51
So, the the cost of Reid's bowl = $3.51