Equations
A line fit passes through points: (2,28) and (6,20)
Find the slope.
m=-2
Equation: y=−2000x+28000
Predict the value when
x=4
y=20000
Fuel efficiency equation: y=−9/1000x+62
Predict MPG for 3500 pounds.
y=30.5 MPG
A line fit passes through: (3,25) and (7,13)
Find the equation in form of y=mx+b.
y=−3x+34
Equation: y=−2500x+32000
Predict price for a car that is 6 years old.
y=17000
Fuel efficiency equation: y=−9/1000x+62
Predict MPG for 3750 pounds.
y=28.25 MPG
Henry drew a line fit using points (1000,52) and (3000,34)
Find an equation in form of y=mx+b.
y=−9/1000x+61
Equation: y=−2200x+29000
A car is 7 years old and its actual price was is $12,000
Was the prediction accurate? If not state by how much the prediction was wrong.
Prediction overestimated by $1600
A 3800 pound car has actual fuel efficiency of 26 MPG
Equation: y=−9/1000x+62
Compare predicted and actual values.
Prediction overestimated by 1.8 MPG
A student says the equation for points (2000,46) and (4000,28) is
y=−9x+64
Is the student correct? If not, write the correct equation.
Correct equation:
y=−9/1000x+64
Student is incorrect.
Equation: y=−1900x+26000
Predict price for a 9 year old car and compare it to the actual price of $8,500. Then state by how much your prediction was wrong
Prediction = $8,900
Prediction error = $400
Interpret the slope of:
y=−9/1000x+62
For every 1000 pound increase in weight, fuel efficiency decreases by 9 MPG
A line fit passes through: (2,26793) and (5,20000)
Find an equation of the line fit. Round slope to nearest hundredth.
y=−2264.33x+31321.65
Equation: y=−2400x+31000
Three cars have actual prices:
Which car is predicted MOST accurately?
7 year old car
Explain why it does NOT make sense to interpret the y-intercept in:
y=−9/1000x+62
it would represent a car weighing 0 pounds doing 62 MPG