Overview

This topic introduces how data is organized, visualized, and interpreted. You'll learn to read charts, summarize datasets, calculate basic statistics, and understand the concept of normal distribution. These skills are essential for interpreting patterns and making informed decisions using real-world data.

Key Concepts and Structures

• Types of Data Displays:
  • Bar Graphs: compare categories
  • Pie Charts: show parts of a whole
  • Line Graphs: track trends over time
  • Histograms: show frequency distribution for intervals
  • Scatterplots: examine relationships between variables
• Measures of Center:
  • Mean: Arithmetic average
  • Median: Middle number when sorted
  • Mode: Most frequent number
• Range: Difference between maximum and minimum values
• Standard Deviation (Conceptual): Describes how spread out the data is from the mean
• Normal Distribution: Symmetrical, bell-shaped curve where most values cluster around the mean
• Outliers: Unusually high or low values that may skew results

Step-by-Step Example

Problem: Find the mean, median, and mode of the dataset:
8, 12, 10, 8, 14

Step 1: Mean:
(8 + 12 + 10 + 8 + 14) / 5 = 52 / 5 = 10.4

Step 2: Median (sort first):
8, 8, 10, 12, 14 → middle value is 10

Step 3: Mode:
8 appears most often

Final Answer: Mean = 10.4, Median = 10, Mode = 8

Quick Tip