2.2: Relating Graphs to Events We use graphs as a way to “picture” information. A graph makes it easier to spot trends and patterns. When reading a graph, pay attention to the labels on the axes.

Types of Data Continuous: involves a measurement –Temperature, length, weight Your weight from birth to age 14 Discrete: involves a count –Number of People or objects Time you get up each morning for one week

This graph shows someone taking a walk in the neighborhood. Describe what it shows by labeling each part. Relating Graphs to Events The graph relates: distance from home to time spent walking. At first, the person walks slowly away from home. She picks up speed. Then she stands still for a while because her distance remains constant. She walks quickly away from home. She rests for a while. She heads back home at a quick pace. She rests again. She finishes her trip home at a slower pace.

A pelican flies above the water searching for fish. Sketch a graph of its altitude from takeoff from shore to diving to the water to catch a fish. Label each section. Relating Graphs to Events 5-1 The graph relates how high the bird flies with respect to time. The bird takes of from a height of zero and slowly gains height. The bird “cruises” at a constant height for a long period of time. The bird returns to a height of zero quickly, presumably he is diving for a fish.

Which graph in Example 3 could show a car sitting at a stoplight? Graph I indicates a quantity that does not change with time. Graph II shows an increase over time. A car sitting at a stoplight would stay in the same place over time. Graph I could show a car sitting at a stoplight.

Extra Practice ALGEBRA 1 LESSON 5-1 Use the graph for questions 1–3. 1.Why does this graph not start at zero? 2.Why is the graph not a straight slanted line? 3.What does the flat part at the top of the graph represent? A person’s height is not zero when born. A straight line represents a constant rate of growth and people do not grow that way. The person has stayed the same height over a long period of time. a jagged curve 4.Would a horizontal line, a straight slanted line, a curve, or a jagged curve best represent the calories you burn during the day? 5-1