Chapter 9 - Section 9.3 - Assess Your Understanding - Vocabulary and Skill Building - Page 459: 6

$χ2_{0.975} = 12.401$ $χ2_{0.025} = 39.364$

n = 25, df = n-1 = 24, Confidence level 95% α = 1 - 0.95 = 0.05 α/2 = 0.025, 1 - α/2 = 0.975 Using table-VII of the book we have: $χ2_{1-α/2} = χ2_{0.975} = 12.401$ $χ2_{α/2} = χ2_{0.025} = 39.364$