Transcript FCAT Friday

FCAT Friday
DATA Analysis
Assignment #37 & #33 (4th Period)
Types of Graphs:
1. LINE GRAPHS
Most useful in displaying data or information that changes continuously
over time
Summarize how two or more pieces of information are related and how
they vary depending on one another
2. BAR GRAPHS and HISTOGRAMS
Allow:
– Comparison of groups of data
– Generalizations to be made about the data quickly
Bar Graphs
Illustrate discrete data (distinct categories)
Drawn with horizontal or vertical bars
Histogram
a bar graph with the adjacent bars
touching each other.
usually drawn only with vertical bars.
used to illustrate continuous data
(there are no gaps between the bars)
No. of Students
3. PIE CHARTS
• Show the component parts of a whole(%)
• Easy to grasp.
Figure 2. Music preferences in young adults 14 to
19
STEPS IN GRAPHING
STEP 1: Identify the dependent and independent
variables.
STEP 2: Numbering the axes.
STEP 3: Assign values to the origin of the graph.
STEP 4: Number each square/line along each axis.
STEP 5: Label both axes.
STEP 6: Title the graph.
STEP 7: Plot the data points.
STEP 8: Connect the data points.
STEP 1: Identify the Dependent and Independent Variables.
A. Dependent variable
Goes on the Y axis (vertical)
Should be on the left side
of the graph.
Depth
(m)
Bubbles / minute
Plant A
Bubbles / minute
Plant B
2
29
21
5
36
27
10
45
40
16
32
50
25
20
34
30
10
20
B. Independent variable
Goes on the X axis (horizontal)
Should be on the BOTTOM of the
graph.
STEP 2: Numbering the axes.
The scales must include all the data points.
The scales should start with 0 and increase based on
intervals such as: multiples of 2, 5, 10, 20, 25, 50, or
100.
The scale of numbers will be dictated by data values.
STEP 2: Numbering the axes cont’d.
How to determine scales:
1. Decide how many squares/lines of the graph paper to use for each axis.
2. Decide how many units of measure each square/line will represent.
• Determine the range of the data to be graphed.
I.V. Range: 2 m to 30 m
Depth
(m)
Bubbles / minute
Plant A
Bubbles / minute
Plant B
2
29
21
5
36
27
I.V.: 28 m
10
45
40
D.V.: 40 bubbles/min.
16
32
50
25
20
34
30
10
20
D.V. Range: 10 to 50 bubbles/min.
• Subtract the lowest data value from
the highest data value.
STEP 2 cont’d:
• Decide how tall and wide to make the graph
(# of lines/squares to use). Choose a number
that is slightly higher or easily divided by the
range of data.
Range of I.V. data: 28 m
Depth
(m)
Bubbles / minute
Plant A
Bubbles / minute
Plant B
2
29
21
5
36
27
10
45
40
16
32
50
25
20
34
30
10
20
use 30 lines for the I.V.
Range of D.V. data: 40 bubbles/min.
use 20 lines for the D.V.
• Divide the range by the number of squares/lines, then round off to the next larger
convenient number.
28 m ÷ 30 lines = 0.93 m/line round to 1m/line each line on the x-axis will represent
1 meter.
40 bubble/min. ÷ 20 lines = 2 bubbles/min./line each line on the y-axis will
represent 2 bubbles/min.
• By using intervals of one, two, four, five, ten, 0.5, 0.4, 0.2, 0.1, etc., you can
easily judge where to place data points that fall between the written numbers
on the axes. This allows plotting with precision.
STEP 2 cont’d:
• The intervals on each axis MUST be consistent (the same the
entire length). The interval from one line/box to the next should
be the same.
Plant A
Plant B
60
No. of Bubbles (min.)
Each line is 10 bubbles/min.
apart from each other.
Bubbles/min. vs. Depth
50
40
30
20
10
0
Each line is 1 meter apart
from each other.
2
4
6
8
Depth (m)
10
STEP 3: Assign values to the origin of the graph.
Begin the y-axis at a
number that is just
below the lowest data
value.
60
Plant A
Plant B
No. of Bubbles (min.)
Begin the x-axis at
zero.
Bubbles/min. vs. Depth
50
40
30
20
10
0
2
4
6
8
Depth (m)
10
STEP 4: Number each square/line along each axis.
Write in the numbers on the x- and y-axes.
• Use the values determined Steps 2 & 3.
• This should be an easy step if the two previous steps have been carried
out with care.
NOTE the actual data points do not necessarily appear as part
numerical scales on the axes.
of the
• On a Line Graph: on both axes, label the lines NOT the space.
• On a Bar Graph: on the x-axis, label the boxes not the lines.
Bubbles/min. vs. Depth
Plant A
Plant B
No. of Bubbles (min.)
60
50
40
30
20
10
0
2
4
6
8
Depth (m)
10
STEP 5: Label both axes.
Plant A
Plant B
No. of Bubbles (min.)
Both the quantity measured and the
units used must be part of each axis
label.
The units are placed in parentheses
afterBubbles/min.
or below
the label for the quantity
vs. Depth
measured.
60
50
40
30
20
10
0
2
4
6
8
Depth (m)
10
STEP 6: Title the graph.
The title should give a brief, clear description of the experiment
represented by the data on the graph.
Other people should be able to figure out what is plotted without
asking you.
Bubbles/min. vs. Depth
Plant A
Plant B
No. of Bubbles (min.)
60
50
40
30
20
10
0
2
4
6
8
Depth (m)
10
STEP 7: Plot the data points.
Mark each data point with a
clear, accurately placed symbol
(usually a dot).
Use a legend or key to explain
which color goes with which set
of data.
60
Plant A
Plant B
No. of Bubbles (min.)
If multiple sets of data are
being graphed on the same
graph, use colored pencils or
pens for the different sets of
data.
Bubbles/min. vs. Depth
50
40
30
20
10
0
2
Do NOT use markers or
highlighters to draw your graph.
4
6
8
Depth (m)
10
STEP 8: Connect the data points
Plant A
Plant B
Use a straight
edge (ruler) to
draw a continuous
line.
Bubbles/min. vs. Depth
60
No. of Bubbles (min.)
Draw a neat,
straight line that
connects all the
data points.
50
40
30
20
10
0
2
4
6
8
Depth (m)
10