HR Hypothesis Testing

Part 2:

H0 (Null Hypothesis): The mean Monthly Income = 6,200

Ha (Alternative Hypothesis): The mean Monthly Income ≠ 6,200

Q2.1: Sample mean = 6,200

Q2.2: p-value = 0.000 (≈ 0)

Q2.3: Reject the null hypothesis.
Conclusion for CEO: The data shows a statistically significant difference in monthly income from 6,200.

Part 3

• H0 (Null Hypothesis): The attrition rate = hypothesized value (no increase)

• Ha (Alternative Hypothesis): The attrition rate > hypothesized value

Q3.1: Sample proportion ≈ 0.16

Q3.2: One-tail p-value ≈ 0.000

Q3.3: Reject the null hypothesis.
Conclusion: There is strong statistical evidence that attrition is higher than expected, so the HR director should be concerned

Part 4

• H0 (Null Hypothesis): Department and Attrition are independent (no relationship)

• Ha (Alternative Hypothesis): Department and Attrition are related

Q4.1: Research & Development

Q4.2: Chi-square ≈ 10.706, df = 2, p-value ≈ 0.005

Q4.3: Reject the null hypothesis.
Conclusion: There is a significant relationship between department and attrition (attrition differs by department).