HR Hypothesis Testing

1

Part 2 Annotation

Null Hypothesis (H0) Our company's Monthly Income does not significantly differ from the national average of $6,200.

Alternative Hypothesis (Ha).

Our company's Monthly Income significantly differs from the national average of $6,200.

Q2.1: What is the sample mean of the Monthly Income for our cleaned dataset? •$5,502.763

Q2.2: What is the p-value for this two-tail test? • 0.0

Q2.3: Based on a significance level of 0.05 and the p-value rule from Chapter 8, do you reject or fail to reject the null hypothesis?

We reject the null hypothesis

Write a one-sentence conclusion for the CEO

The data shows that our Money Incomes does differ significantly from the normal with a 95% confidence level.

Part 3

Null Hypothesis (H0) our attrition proportion is not significantly greater than 0.12?

Alternative Hypothesis (Ha). our attrition proportion is significantly greater than 0.12?

Q3.1: What is the sample proportion of attrition (the Mean of Attrition_Numeric) 0.171

Q3.2: What is the calculated one-tail p-value? Numeric)? •0

Q3.3: Based on a significance level of 0.05, do you reject or fail to reject the null hypothesis? Reject

Is there statistical evidence for the HR director to be worried?

Yes, there is evidence

4

Null Hypothesis (H0) Attrition is independent of the Department that a person works.

Alternative Hypothesis (Ha). Attrition is dependent on the Department a person works.

Q4.1: Looking at the Crosstab view, which department had the highest raw count of “Yes” for Attrition? Research & Development

Q4.2: Look at the Statistics output. What is the Chi-Square test statistic, 9.88

the degrees of freedom (df), 2

and the exact p-value? 0.007

Q4.3: Using a 0.05 significance level, do you reject or fail to reject the null hypothesis? Reject

What does this mean in plain English regarding Departments and Attrition?

The department a person works in affects the attrition rate.