Using proportions, it is found that she should expect 4 of the next 12 appliances to be ovens.
A proportion is a fraction of a total amount, and the measures are related using a rule of three.
In this problem, we have that out of 15 items, 5 are ovens. How many will be out of 12? To find out, we start with the rule of three.
15 items - 5 ovens
12 items - x ovens
Applying cross multiplication:
15x = 60
x = 4.
Hence, 4 of the next 12 appliances to be ovens.
More can be learned about proportions at https://brainly.com/question/24372153