Data Analysis

Reading bar, line, pie, dot, and scatter plots, and spotting misleading graphs.

This page is a free outline of what the Data Analysis lesson covers — it is not the lesson itself. The interactive lesson, practice, quizzes, and AI Tutor are inside the app.

This lesson covers

• Average Rate of Change ⓘThe average rate of change is how much the output changes per unit of input between two points — the same as the slope of the line connecting them: (change in y) ÷ (change in x).
• Bar Graphs and Histograms ⓘA bar graph compares separate categories with bars whose heights show their values; a histogram looks similar but groups a range of numbers into intervals to show how data is distributed.
• Choosing the Right Statistical Measure (Mean, Median, Mode, Range) ⓘWhich measure fits depends on the data: the mean for evenly spread values, the median when outliers would skew it, the mode for the most common value, and the range for spread.
• Circle Graphs (Pie Charts) ⓘA pie chart shows how a whole is divided into parts, each slice a percentage of the total — the full circle is 100%.
• Dot Plots ⓘA dot plot stacks a dot for each data value above a number line, so you can see how often each value occurs and how the data clusters.
• Line Graphs and Trends ⓘA line graph connects points over time to show how a value rises or falls, making trends and changes easy to spot.
• Making Predictions from Data ⓘMaking predictions from data uses the pattern in a graph or table — like a line of best fit — to estimate values beyond what was measured.
• Mean (Average) →
• Weighted Average ⓘA weighted average counts some values more than others by their frequency or weight — like a grade where tests count more than quizzes — found by multiplying each value by its weight, adding, then dividing by the total weight.
• Median →
• Misleading Graphs ⓘA misleading graph distorts the data — a cut-off axis, uneven scale, or stretched shape — to make a difference look bigger or smaller than it really is.
• Mode →
• Percent – Finding a Percent of a Number →
• Percent – Increase and Decrease →
• Percent – Word Problems ⓘPercent questions in sentence form — find the part, the whole, and the percent.
• Range (Statistics) ⓘThe range is the difference between the largest and smallest values (max − min). It measures how spread out the data is, not its center.
• Reading Data Tables ⓘA data table organizes values in labeled rows and columns; reading it means finding the cell where the row and column you need meet.
• Scatter Plots and Correlation ⓘA scatter plot plots paired values as points to reveal a relationship: an upward pattern is positive correlation, downward is negative, and a scattered cloud means little or no correlation.

Linked concepts (purple →) have a full explanation. Hover or tap a dotted ⓘ concept for a quick definition.