# Topic 11 - Measurement and Data Processing - 11.2 Graphical Techniques.

```TOPIC 11 – MEASUREMENT AND DATA PROCESSING
Name:
Date:
11.2 GRAPHICAL TECHNIQUES
1. Define the following:
a. Independent variable
b. Dependent variable
c. Positive correlation
d. Negative correlation
2. What is the range of the coefficient of correlation?
3. Sketch diagrams representing a:
a. Positive correlation
b. Negative correlation
c. No correlation
4. Indicate what you would use as variables on the X and Y axes when plotting graphs of the
following conditions and assign the variables as dependent or independent.
a. Changing the temperature at which a reaction takes place to observe the effect on the
reaction rate
b. Observing the pH change upon the addition of base in titration
c. Radioactive nuclei of uranium-235 decaying over time
5. Identify the correlation in each graph below. Label each graph as “positive”, “negative”,
or “no correlation”.
6. On the graphs that have a positive or negative correlation, draw an oval surrounding all
points.
7. Draw the a line through the oval (end to end).
Definition: Line of Best Fit
8. An investigation into the mass of oxygen required to completely react with a fixed amount of
magnesium produced the following results:
Mass Mg/ g
0.50
1.00
1.50
2.00
2.50
3.00
Mass O2/g
0.33
0.66
0.99
1.30
1.60
1.90
a. Draw a graph to show the results
b. Extrapolation – Determine graphically what would be the mass of oxygen if the mass of
magnesium were 3.50 g.
c. Interpolation – What would be the mass of magnesium if the mass of oxygen required
is 1.75 g?
d. Identify the correlation in the graph.
Check Point
Hours (x)
Miles (y)
1
35
2
29
Biking Home
3
4
5
26
20
16
6
9
7
6
8
0
1. Graph a scatter plot of the data relating time and distance on the grid below. Be
sure to label the grid appropriately.
2. Draw the line of best fit for the data above. Write down the mathemical expression of
the line of best fit using y = mx + c
```