Test scores are plotted against hours spent studying. The fitted line is y = 5x + 52, with x in hours and y in points. What does the 5 mean here?

A shop plots cups of hot chocolate sold against the outside temperature in degrees Celsius. The fitted line is y = -2x + 60. Interpret the slope in this situation.

A burning candle's height in centimeters (y) is plotted against minutes alight (x). The fitted line is y = -0.4x + 20. What does -0.4 tell you about the candle?

Shipping cost in dollars (y) is plotted against parcel mass in kilograms (x). The fitted line is y = 1.5x + 8. What are the units of the slope 1.5?

A forester fits y = 2.5x + 10 to the plot, where x is a tree's age in years and y is its trunk circumference in centimeters. Interpret the slope.

Resting heart rate in beats per minute (y) is plotted against daily minutes of exercise (x). The fitted line is y = -0.3x + 78. What does the slope report?

Pizza prices in dollars (y) are plotted against the number of toppings (x). The fitted line is y = 1.25x + 9. What does the 9 mean in this situation?

Shoe length in centimeters (y) against height in centimeters (x) gives y = 0.16x + 2, from data running 150 to 175 centimeters tall. Why is the y-intercept not meaningful here?

A car's value in dollars (y) is plotted against its age in years (x), giving the fitted line y = -1800x + 22000. What does 22000 represent?

A student says the 25 in y = 4x + 25 shows how fast a pool fills. Here x is minutes since the pump started and y is water depth in centimeters. What does 25 actually show?

Catering costs in dollars (y) are plotted against guests (x), giving y = 18x - 40. The data run from 10 to 60 guests. What does the y-intercept of -40 tell the caterer?

Puppy mass in kilograms (y) is plotted against age in months (x), with fitted line y = 1.4x + 2. The data cover 1 to 10 months. Predict the mass of a 6-month-old puppy.

Cricket chirps per minute (y) are plotted against air temperature in degrees Celsius (x), with fitted line y = 6x - 40. The data run from 15 to 30 degrees. Predict the rate at 22 degrees.

Salary in thousands of dollars (y) is plotted against years of experience (x). The fitted line is y = 2.5x + 38 and the data cover 2 to 12 years. Which salary does the line predict at 8 years?

Free throws made out of 50 (y) are plotted against practice sessions (x). The fitted line is y = 2x + 8 and the data cover 5 to 20 sessions. How many does the line predict after 15 sessions?

The percent of households with a landline (y) is plotted against years since 2010 (x). The fitted line is y = -3.5x + 62 and the data run to 2020. What percent does the line predict for 2018?

Tomato yield in kilograms (y) is plotted against fertilizer in grams per plant (x). The fitted line is y = 0.05x + 1.2 and the data cover 10 to 60 grams. Predict the yield at 40 grams.

Heights of children aged 5 to 12 give the fitted line y = 6x + 80, with x the age in years and y the height in centimeters. Someone predicts a 40-year-old's height from it. Why is that unreliable?

A dieter's mass in kilograms (y) over weeks 0 to 12 (x) fits the line y = -0.6x + 92. What is wrong with using that line to predict the mass at week 200?

Sunflower heights recorded on days 5 to 30 fit the line y = 3x + 10, with x the day and y the height in centimeters. A student uses the line to find the height on day 730. What does that show?