The distance vs. time graph of a car moving at constant speed should be a straight line. why do the data points in the graph plotted from observing the motion not fall right on the line? a. the distance is not exactly proportional to time even if the speed is exactly constant. b. the distance and time are proportional only if the correct units of meters an seconds are used. c. data points can never look like they fall right on a straight line. d. the measurements are inexact.

For a science project, a high school research team conducted a survey of local air temperatures. based on the results of the survey, the found that the average temperatures were around 10 degrees higher than expected. this result was wrong. the trouble with the survey was that most of the locations were exposed to direct sunlight and located over asphalt or sand, which resulted in higher temperatures than normal. this is a classic example of an error in which phase of inferential statistics?