Pollock - Chapter 8-9

State the Null Hypothesis (H0) and Alternative Hypothesis (Ha).

6200

6200

• Q2.1: What is the sample mean of the Monthly Income for our cleaned dataset? 5526.79

• Q2.2: What is the p-value for this two-tail test? 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? Write a one-sentence conclusion for the

CEO.

Reject the null

we are paying about $673 less than what is the industry standard

State the Null Hypothesis (H0) and Alternative Hypothesis (Ha).

0.12

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?

3.34157895 is what i get when dividing the output by 2

• Q3.3: Based on a significance level of 0.05, do you reject or fail to reject the null hypothesis? Is there statistical evidence for the HR director to be worried?

The answer above does not make sense in the context of a p value. If i change how i view the number it comes out as a 0. If the second result is true then we reject the null

I believe my data is not coming out as it should but in its current state there is nothing to be worried about.

KNIME automatically calculates a two-tail pvalue. Because our Alternative Hypothesis uses a “greater than” symbol, this is a one-tail test. To find the one-tail p-value, you must manually divide the KNIME p-value by 2.

State the Null Hypothesis (H0) and Alternative Hypothesis (Ha).

• Q4.1: Looking at the Crosstab view, which department had the highest raw count of

“Yes” for Attrition?

Research and development

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

of freedom (df), and the exact p-value?

9.84

2

0.007

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

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

I reject the hypothesis

There is nothing to be worried about with attrition of your employees