If its 21 inches then rounding to the nearest who should be 21 inches
Answer:

Where y is the total amount earned, m the amount for each extended warranty and b the fixed cost and x the total amount of TVs
For this case the value of x = 16 since we have 16 Tvs with extended warranties and we can do this:

and solving for b we got:

And then we can conclude that she earns 60 for each TV
Step-by-step explanation:
For this case we can set a linear model like this:

Where y is the total amount earned, m the amount for each extended warranty and b the fixed cost and x the total amount of TVs
For this case the value of x = 16 since we have 16 Tvs with extended warranties and we can do this:

and solving for b we got:

And then we can conclude that she earns 60 for each TV
Send a better photo or tell me what I’m suppose to be answering
A foot is 12 in so a fraction could be 3/12