5%

Can you tell me what you want to cover with "5%"? Here are quick areas and a tiny practice set. Pick a topic and I’ll tailor more problems.

Key ideas

• 5% as a decimal: 5% = 0.05
• "X% of Y" = (X/100) × Y
• Increase by 5%: Y × 1.05
• Decrease by 5%: Y × 0.95
• Percentage change from A to B: ((B − A) / A) × 100%

Quick practice

1. Convert 5% to decimal. Answer: 0.05
2. What is 5% of 240? Answer: 12
3. Increase 200 by 5%. Answer: 210
4. Decrease 120 by 5%. Answer: 114
5. A value changes from 150 to 165. What is the percentage change? Answer: 10%

If you’re studying statistics:

• Alpha = 0.05 means a 5% risk of rejecting a true null hypothesis (type I error)
• p-value < 0.05 → reject H0 at the 5% significance level Want a quick set of stat problems at the 5% level, or more percentage practice? Tell me your topic and I’ll tailor it.