Chapter 8 and 9 Assignment

Null Hypothesis: Our company's average monthly income is consistent with the national average.

Alternative Hypothesis: Our company's average monthly income is significantly different than the national average.

Q2.1: Sample mean = $6,200

Q2.2: p-value = 0.0001

Q2.3: We should reject the null hypothesis because the p-value is less than the significance level.

Null Hypothesis: Our attrition proportion is 0.12.

Alternative Hypothesis: Our attrition proportion is significantly greater than 0.12.

Q3.1: 0.12

Q3.2: 0.0001

Q3.3: I would reject the null hypothesis because the p-value was less than the significance level. There is no statistical evidence for the HR director to be worried.

Null Hypothesis: Attrition is independent of department.

Alternative Hypothesis: Attrition depends on the department.

Q4.1: The Research Department

Q4.2: 9.844, 2, 0.007

Q4.3: Reject the null because the p-value is less than the significance level.