MA 214 Probability and Statistics for Business

Dr. Ed Donley

Answers to Hypothesis Test Review

1. Proportions. H_o: p < .40, Ha: p > .40. Rejection region: z > 1.645. Test statistic: z = 1.67 . Conclusion: Reject H_o.

2. One population mean using z. H_o: m < 6, H_a: m > 6. p = .0228.

3. One population mean using t. H_o: m = 42000, H_a: m < 42000. Rejection region: t < -1.711. Test statistic: t = -2 . Conclusion: Reject H_o.

4. Proportions. H_o: p < .50, H_a: p > .50. Rejection region: z > 1.645. Test statistic: z = 1.41 . Conclusion: Draw no conclusion.

5. One population mean using z. H_o: m = 10, H_a: m 10. Rejection region: z > 1.96 or z < -1.96. Test statistic: z = -14.61. Conclusion: Reject H_o.

6. Two population means using matched pairs. H_o: m₁- m₂ > 0, H_a: m₁- m₂ < 0. Rejection region: t < -2.132. Test statistic: z = -1.41 . Conclusion: Draw no conclusion.

7. One population mean using z. H_o: m > 2.50, H_a: m < 2.50. Rejection region: z < -1.645. Test statistic: z = -3.14 . Conclusion: Reject H_o.

8. Proportions. H_o: p < .45, H_a: p > .45. Rejection region: z > 1.645. Test statistic: z = 1.31 . Conclusion: Draw no conclusion.

9. Two population means using matched pairs. H_o: m₁- m₂ < 0, H_a: m₁- m₂ < 0. Rejection region: t < -2.132. Test statistic: z = -6.15. Conclusion: Reject H_o.

10. Two population means using z with independent samples. H_o: m₁- m₂ = 0, H_a: m₁- m₂ 0. Rejection region: z > 1.96 or z < -1.96. Test statistic: z = -4.64. Conclusion: Reject H_o.

11. One population mean using t. H_o: m < 2500, H_a: m > 2500. Rejection region: t > 1.44. Test statistic: t = 1.63. Conclusion: Reject H_o.

12. One population mean using t. H_o: m > 3, H_a: m < 3. Rejection region: t < -1.761. Test statistic: t = -1.94. Conclusion: Reject H_o.

13. Two population means using t and s_p with independent samples. H_o: m₁- m₂ = 0, H_a: m₁- m₂ 0. Rejection region: t < -2.017 or t > 2.017. Test statistic: t = -1.94. Conclusion: Draw no conclusion.