What You Will Practice
Pre-statistics builds the foundation for understanding data, graphs, and basic probability. These skills help students read information, make comparisons, and prepare for college statistics.
Mini Lesson
1. Types of Data
Quantitative data are numbers. Qualitative data are categories or labels.
Quantitative: 72 inches, 15 parts, 8.5 grams
Qualitative: red, blue, pass/fail, material type
2. Mean
The mean is the average.
Example: 5, 7, 8, 10 → sum = 30 → mean = 30 ÷ 4 = 7.5
3. Median
The median is the middle value after the numbers are placed in order.
Example: 2, 9, 5 → ordered: 2, 5, 9 → median = 5
4. Mode
The mode is the value that appears most often.
Example: 3, 4, 4, 6, 7 → mode = 4
5. Range
Range measures how spread out the data are.
Example: 12, 5, 20, 8 → range = 20 - 5 = 15
6. Simple Probability
Probability compares favorable outcomes to total outcomes.
Example: 2 blue balls out of 5 total → probability = 2/5 = 0.4 = 40%
Interactive Pre-Statistics Practice
Choose a topic and practice with instant feedback. For decimal answers, round to two decimal places if needed.
quantitative or qualitative.
For probability, type a decimal such as 0.4 or a percent such as 40%.
Mastery Check
Before moving to Chapter 5, students should be able to do the following.
Data Types
I can identify quantitative and qualitative data.
Mean
I can calculate the average of a dataset.
Median
I can order data and find the middle value.
Mode
I can find the value that appears most often.
Range
I can subtract the smallest value from the largest value.
Probability
I can calculate favorable outcomes divided by total outcomes.