Prerequisites: Are You Ready?
What You Need to Know Before Starting
This book assumes no prior statistics knowledge and no programming experience. However, you do need some basic algebra skills. The diagnostic assessment below will help you determine if you're ready — or if a quick refresher is in order.
Diagnostic Self-Assessment
Try each problem. If you can answer at least 8 out of 12 correctly, you're ready to start Chapter 1. If you score lower, see the "Refresher Resources" section below — a few hours of review will get you where you need to be.
Part 1: Numbers and Operations
1. Calculate: 15% of 240
Answer
**36.** Multiply 240 × 0.15 = 36. (To convert a percentage to a decimal, divide by 100.)2. Convert 3/8 to a decimal.
Answer
**0.375.** Divide 3 ÷ 8 = 0.375.3. What is the order of operations for: 2 + 3 × 4?
Answer
**14.** Multiplication before addition: 3 × 4 = 12, then 2 + 12 = 14 (not 20).4. Round 3.14159 to two decimal places.
Answer
**3.14.** The third decimal (1) is less than 5, so round down.Part 2: Basic Algebra
5. Solve for x: 2x + 5 = 17
Answer
**x = 6.** Subtract 5 from both sides: 2x = 12. Divide by 2: x = 6.6. If y = 3x - 7, what is y when x = 5?
Answer
**y = 8.** Substitute: y = 3(5) - 7 = 15 - 7 = 8.7. Simplify: (12 - 8)² ÷ 2
Answer
**8.** First: (12 - 8) = 4. Then: 4² = 16. Then: 16 ÷ 2 = 8.Part 3: Reading Graphs and Tables
8. A bar chart shows the following sales by region: North = $50K, South = $30K, East = $45K, West = $25K. Which region had the highest sales? What was the total?
Answer
**North** had the highest sales ($50K). Total = $50K + $30K + $45K + $25K = **$150K**.9. A table shows that 60 out of 200 students prefer online classes. What percentage prefer online classes?
Answer
**30%.** Calculate: 60 ÷ 200 = 0.30 = 30%.Part 4: Proportional Reasoning
10. If a recipe serves 4 people and calls for 2 cups of flour, how much flour do you need for 10 people?
Answer
**5 cups.** Set up the proportion: 2/4 = x/10. Cross multiply: 4x = 20, so x = 5.11. A survey finds that 3 out of every 5 adults exercise regularly. In a city of 100,000 adults, approximately how many exercise regularly?
Answer
**60,000.** Calculate: (3/5) × 100,000 = 60,000.12. If the price of a $80 item is reduced by 25%, what is the sale price?
Answer
**$60.** Calculate the discount: 25% of $80 = $20. Sale price: $80 - $20 = $60.How Did You Do?
| Score | Assessment | Recommendation |
|---|---|---|
| 10-12 | Ready to go | Start Chapter 1 with confidence |
| 8-9 | Nearly ready | Review the topics you missed, then start |
| 5-7 | Needs a refresher | Spend 2-4 hours on the resources below, then start |
| Below 5 | Needs preparation | Work through a pre-algebra review before starting this book |
Refresher Resources
If you need a brush-up on any of the prerequisite skills, these free resources are excellent:
Fractions, Decimals, and Percentages
- Khan Academy: "Arithmetic" section — start with "Fractions" and "Percentages" (khanacademy.org)
- Estimated time: 2-3 hours
Basic Algebra
- Khan Academy: "Algebra Basics" — focus on "Solving basic equations" and "Evaluating expressions" (khanacademy.org)
- Estimated time: 2-4 hours
Reading Graphs and Tables
- Khan Academy: "Statistics and probability" → "Displaying and describing data"
- Estimated time: 1-2 hours
Order of Operations
- Remember PEMDAS: Parentheses, Exponents, Multiplication/Division (left to right), Addition/Subtraction (left to right)
- Estimated time: 30 minutes
What You Do NOT Need
Just to be absolutely clear about what is not required:
- ❌ Calculus — not even a little bit. We never take derivatives or integrals.
- ❌ Prior statistics courses — this book starts from zero.
- ❌ Programming experience — we teach you Python from scratch in Chapter 3.
- ❌ A scientific calculator — Python and Excel will handle all computation.
- ❌ A "math brain" — statistical thinking is a skill, not an innate talent. Research consistently shows that with the right instruction and practice, anyone can learn it.
If you passed the diagnostic, turn the page. Let's begin.