Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Data Tables: Tables are used to organize observations. The independent variable (what you change) is placed in the left column, and the dependent variable (what you measure) is placed in the right column. Units should be written in the header, e.g., , , or .
Bar Charts: These are used for categorical or discrete data (e.g., types of fruit or number of siblings). Bars should have equal width, and there must be gaps between the bars.
Line Graphs: These are used for continuous data, often showing changes over time (e.g., plant growth over days). Points are plotted and connected with a line to show a trend.
Axes Labeling: The horizontal axis (-axis) represents the independent variable. The vertical axis (-axis) represents the dependent variable. Both must have clear labels and units.
Scale Selection: A scale must be consistent. For example, if on the graph represents , every must represent exactly to avoid distorting the data.
📐Formulae
💡Examples
Problem 1:
A student measures the temperature of water every minute for minutes as it cools. The readings are , , , , and . Should this data be recorded in a bar chart or a line graph?
Solution:
A line graph.
Explanation:
Since time and temperature are both continuous variables, a line graph is the best way to show the trend of the water cooling over the minute period.
Problem 2:
Calculate the mean (average) height of three plants measuring , , and .
Solution:
Explanation:
Using the formula:
Problem 3:
In a data table for an experiment testing how the amount of water affects plant height, which column should 'Amount of Water ()' be placed in?
Solution:
The first column (left side).
Explanation:
The amount of water is the independent variable (the factor being changed by the scientist), which by convention is placed in the first column of a data table.