Practice Assignment Chapters 8&9

Part 1:

Data Import and Data Cleaning

Part 2:

Two-Tail Hypothesis Test of a Mean

Q2.1: 5,502.763

Q2.2: 0

Q2.3: Based on a significance level of 0.05 and on the p-value in this two-tale test I reject the null hypothesis.

Q2.3:

Part 3:

One-Tail Hypothesis test of a Proportion

Q3.1: 0.171

Q3.2: 0

Q3.3: Based on the significance level of 0.05 I reject the null hypothesis. Due to the calculated one-tail p-value being 0, the HR director should be somewhat concerned.

Part 4:

Chi-Square Test of Independence

Q4.1: Research & Development

Q4.2: Chi-square test statistic = 0

df = 2

exact p-value = ?

Q4.3: Based on the level of significance I reject the null hypothesis. In simple terms this means that in some departments attrition is not evenly distributed.