Graphing: Lets Organize the Data! We will cover: Data Tables Line Graphs Bar Graphs Circle Graphs Page 1 INTRODUCTION Whenever data is collected, it is often presented in a meaningful way so that others can view and make sense of it. Often the data will be presented in a data table or a _____. graph

_________ organizing the Data tables are a way of _________ information. pictorial diagrams that Graphs are _______________ numerical data represent ______________. Page 2 As a student, it is important that you master these essential skills: 1. Interpreting and reading graphs 2. Constructing data tables 3.Constructing different

types of graphs (line graphs, bar graphs, circle graphs) Page 3 Interpreting Graphs 1. What information is being shown in this graph? Study the line graph and answer the following questions. This graph shows the effect of different concentrations

of fertilizer on the growth of three different types of plants. Page 4 2. Describe the results shown for corn plants. For corn plants, the higher the concentration of fertilizer, the taller the plants will grow. Page 5 3. Describe the results shown for oak seedlings. As the concentration of fertilizer is increased, growth of oak seedlings is improved, up to a certain point. Page 6 4. Describe the results shown for rose bushes. For rose bushes, increasing the concentration of

fertilizer inhibits plant growth. Page 7 5. At what fertilizer concentration do oak seedlings stop improving? At concentrations above 150 mg/L, oak seedling growth is inhibited. Page 8 6. What was the height of the tallest plant used in this experiment? Corn grew to an average height of around 33 cm when the fertilizer concentration was 250 mg/L. Page 9 7. For which plant is this fertilizer least effective at higher concentrations? Rose bushes.

Page 10 8. Which plant shows the best growth when the fertilizer concentration is 100 mg/L? Oak seedlings Page 11 9. Predict how tall corn plants might be when the fertilizer concentration is 75 mg/L. The plants will be approximately 12 - 13 cm in height. Page 12 10.Consider the three types of plants used in this experiment. What reasons might explain why the results turned out as they did? Possible answers: Plants that produce a large fruit (corn) need more fertilizer. Plants that produce a large woody stem (oak trees) grow best with moderate concentrations of fertilizer. Page 13

Study the bar graph to the right and answer the following questions: 1. Do fish grow to a larger weight in pond water or in tap water? Pond water. 2. Which grow larger, the males or the females? Females 3. What is the average weight of female fish when grown in pond water? Approximately 6.4 g.

Page 14 Study the bar graph to the right and answer the following questions: 4. What is the average weight of male fish when grown in tap water? Approximately 5.5 grams. 5. Why do you suppose the fish grow the best in pond water? Some possible answers might include: The tap water contains chlorine and fluorine, which might affect the growth of fish. Tap water does not contain all the various minerals and ions that might be found in pond water. Page 15 Making a Data

Table As scientists collect data, it must be recorded in an organized fashion. Any time data is collected in an experiment, it is most often presented in a table. The data table must have a title, rows, columns, and heads. The title should be placed at the top and tells the observer what information is contained in the table. At the top of each column should be a head that tells you what information is in the column. Page 16

Example 1: Make a data table for the following information The following data were collected for the growth of a plant. Growth of a plant in centimeters On day 0, there was 0 growth. On day 1, there was 2.0 cm of growth. On day 2, there was 5.3 cm of growth. On day 3, there was 6.1 cm of growth. On day 4, there was 8.4 cm of growth. On day 5, there was 11 cm of growth. In the top row, place the title of your data table. In the next row, place the two column heads.

Day Growth 0 1 0 cm 2.0 cm 2 5.3 cm 3 6.1 cm

4 8.4 cm 5 11 cm In the remaining rows, fill in the data. Page 17 Example 2: Make a data table for the following information The number of cricket chirps was recorded on two different nights at various temperatures (Celsius). On night 1, the following data was obtained: Temp 16, cricket chirps 33; Temp 18, cricket chirps 38; Temp 20, cricket chirps 42; Temp 22, cricket chirps 46; Temp 24, cricket chirps 50. On night 2, the following data was obtained: Temp 16, cricket chirps 32; Temp 18, cricket chirps 36; Temp 20, cricket chirps 41; Temp 22, cricket chirps 43; Temp 24, cricket chirps 51.

The number of cricket chirps recorded at different temperatures In the top row, place the title of your data table. In the next row, place the two column heads. Since data were collected on two different nights, you will need 4 columns. In the remaining rows, fill in the data. Night 1 Temp

# Chirps Night 2 Temp # Chirps 16 33 16 32 18 38

18 36 20 42 20 41 22 46 22

43 24 50 24 51 Page 18 Making a Line Graph Line graphs show data plotted as points that are connected by a line. Line graphs are often used to show change over time and can be used to compare two or more sets of data.

Before a line graph can be constructed, you must identify the two variables that will serve as x and y coordinates on the graph. An easy way to remember this is to ask yourself the questions: What did I know before I did the experiment? What did I learn by doing the experiment? Page 19 Using the grid below, make a line graph using the information in example 1 from above. First determine which variable to place on the horizontal (x) axis and which variable to place on the vertical (y) axis.

Label each axis appropriately. Scale each axis appropriately. Title your graph. The growth of a plant in centimeters Day Growth 0 0 cm 1

2.0 cm 2 5.3 cm 3 6.1 cm 4 8.4 cm 5 11 cm

Plot the points on the graph. Page 20 Your graph should look like this: Page 21 Using the grid below, make a line graph using the information in example 2 from above. Title your graph. Plot the points on the graph. Since this graph will have two different lines, be sure

to label each line. 50 40 30 20 Scale each axis appropriately. Number of Cricket Chirps Recorded at Various Temperatures 10 Label each axis appropriately.

# cricket chirps First determine which variable to place on the horizontal (x) axis and which variable to place on the vertical (y) axis. 16 18 20 22 24

Temp (C) Page 22 Your graph should look like this Page 23 Making a Bar Graph Bar graphs are useful for showing comparisons of data collected by counting. A bar graph has two axes, a horizontal axis and a vertical axis. Generally the horizontal axis is labeled and the vertical axis is divided. The data

are not related so the bars do not touch. Page 24 In the space below, make a bar graph of the following information. 50 60 40 30 20 10 2000 1999 1998 1997

1996 Draw bars showing the appropriate amounts. 1995 Determine which variable to place on each axis. Label each axis. Peaches Picked in an Orchard Kilograms of Peaches In an orchard the following kilograms of

peaches were picked during a 6 year period. Year Title the graph. Page 25 Making a Circle Graph Circle graphs are used less often in science reporting, but they are often seen in newspapers and magazines. A circle graph is a convenient way to show the relative sizes of the parts that form an entire body of

data. Page 26 Suppose that in a particular high school, the number of students taking a science class is as follows: 50% are taking biology, 30% are taking chemistry, 10% are taking physics and 10% are taking some other type of science class. Use the circle below to represent this data in pictorial form. Chemistry 30% Biology 50% Physics 10% Other

10% Page 27 Analysis Questions Under what circumstance would each of the following types of graphs be best used? a) Line Graph: Line graphs are often used to show change over time and can be used to compare two or more sets of data. b) Bar Graph: Bar graphs are useful for showing comparisons of data collected by counting. c) Circle Graphs: Circle graphs are best used to give the viewer an overall or broad picture view of smaller groups of data and how the smaller groups fit into the whole. Page 28 Analysis

Questions 2. How is a graph similar to a data table? Both are methods of organizing information. 3.Does a steep curve on a line graph indicate a rapid or slow rate of change? Rapid. Page 29 Analysis Questions 4. You are conducting a photosynthesis experiment to determine how much oxygen is produced over a 24 hour period of time. You are measuring the oxygen production every hour for 24 hours. a) What type of graph is best used to represent this data? Line graph b) When you construct a graph of your data, which variable will be placed along the x-axis? Time

c) When you construct a graph of your data, which variable will be placed along the y-axis? Oxygen production Page 30 Analysis Questions 5. What is an advantage of using multiple lines on the same graph? It allows you to show comparisons between different groups of data. Page 31