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Question 104632This question is from textbook Algebra I
: This is from 4.7 Challenge: Skills and Applications
Questions 5 & 6
In 1992, 7.6 million music videos were shipped and in 1996, 16.9 million were shipped.
Write an equation you can solve to find the year that the model predicts 25 million music videos will be shipped.
Then solve the equation graphically. Interpret the result.
Things I know: rate of change is 2.325 million per year.
Tried this equation:
25 =2.325x +7.6 (knowing all numbers in millions)
so to graph I got y=2.325x - 17.4
but now I have a negative graph and I know that is wrong.
So I am thinking what I got is x=years later, not the year. How do I get the year in one equation instead of 2?
Thanks for any help.
This question is from textbook Algebra I
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! In 1992, 7.6 million music videos were shipped and in 1996, 16.9 million were shipped.
Write an equation you can solve to find the year that the model predicts 25 million music videos will be shipped.
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You have two points: (2, 7.6) and (6, 16.9)
slope = [16.9-7.6]/[6-2] = 2.325
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Equation form is # of videos = 2.325(year) + b
Nedd to solve for "b":
7.6 = 2.325*2 + b
7.6 = 4.65 + b
b = 7.6-4.65
b = -2.95
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EQUATION:
# of videos = 2.325(year) - 2.95
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find the year that the model predicts 25 million music videos will be shipped.
25 = 2.325(year) - 2.95
27.95 = 2.325(year)
year = 12.02...
The year will be 1990+12 = 2002
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Cheers,
Stan H.
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