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Equations of trend lines: Phone data

Paige collected data on how long she spent on her phone compared to how much battery life was remaining (in hours) throughout the day. Here is the data:
Time spent on phone (hours)123.546789
Battery life remaining (hours)8775.553.52.52.5
She then made this scatterplot:
A scatterplot plots points x y axis. The y axis is labeled Battery life remaining in hours. The x axis is labeled Time spent on phone in hours. Points fall diagonally in a narrow pattern between the points points (1, 8) and (9, 2 and 1 half). All values estimated.
Now she wants a trend line to describe the relationship between how much time she spent on phone and the battery life remaining. She drew three possible trend lines:
A scatterplot plots points x y axis. The y axis is labeled Battery life remaining in hours. The x axis is labeled Time spent on phone in hours. Points fall diagonally in a narrow pattern between the points points (1, 8) and (9, 2 and 1 half). All values estimated. Line A decreases through the points (0, 9) and (8, 3). Line B decreases through the points (0, 6) and (8, 0). Line C decreases passing through the points (0, 5) and (10, 4).
problem 1
Which line fits the data graphed above?
Choose 1 answer:

problem 2
2) Which equation describes the best trend line above?
Choose 1 answer:

problem 3
Use the equation of the trend line to predict the battery life remaining after 3.6 hours of phone use.
Round your answer to the nearest tenth of an hour.
  • Your answer should be
  • an integer, like 6
  • a simplified proper fraction, like 3/5
  • a simplified improper fraction, like 7/4
  • a mixed number, like 1 3/4
  • an exact decimal, like 0.75
  • a multiple of pi, like 12 pi or 2/3 pi
hours

problem 4
Use the trend line to predict the battery life remaining after 20 hours of phone use.
  • Your answer should be
  • an integer, like 6
  • a simplified proper fraction, like 3/5
  • a simplified improper fraction, like 7/4
  • a mixed number, like 1 3/4
  • an exact decimal, like 0.75
  • a multiple of pi, like 12 pi or 2/3 pi
hours

problem 5
Does the prediction from problem 4 seem reasonable in the context of the problem?
Choose 1 answer:

problem 6
What is the best interpretation of the slope of this trend line?
Choose 1 answer:

problem 7
What is the best interpretation of the y-intercept of this trend line?
Choose 1 answer:

Challenge problem
Paige wants to turn her phone off when the battery has 15 minutes remaining, just in case she has an emergency and needs her phone later.
According to the trend line, how long can she spend on her phone before she needs to turn it off?
Round your answer to the nearest tenth of an hour.
  • Your answer should be
  • an integer, like 6
  • a simplified proper fraction, like 3/5
  • a simplified improper fraction, like 7/4
  • a mixed number, like 1 3/4
  • an exact decimal, like 0.75
  • a multiple of pi, like 12 pi or 2/3 pi
hours

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