StatisticsChapter 1 Statistical Reasoning:Investigating a Claim of Discrimination

Section 1.2Discrimination in the Workplace:Inference through Simulation

1.2 Definitions

Inference: a statistical procedure that involves deciding whether an event can reasonably attributed to chance OR if you should look for another explanation.

Simulation: Setting up a model to simulate the actual process and repeating it to see what happens. This is then compared to what actually occurred.

Definitions

Summary Statistics: a single number that condenses and summarizes the data.

Average or Mean is a summary statistic Sum of the data values / # of data values (n)

1.2 Simulation Activity

Simulate selecting 3 employees out of 10 to lay off. Like round 2 of the lay offs from 1.1. How would you do that with simple

materials?

Refer to page 13 for an example simulation.

Follow these steps. The ages to use are written on the

board. Repeat the process 10 times.

Calculator Simulation

Using a TI-83 or higher: Assign each employee a number 1 –

10. Use the “randInt” function to

randomly select a value from 1-10. MATH key PRB randInt(1,10,n) (start, end, n

selections) What if you select the same number

twice?▪ randInt(1,10,6): take the first 3 non-

duplicated values.

1.2 Simulation Reporting

Create a classroom Dot Plot of your averages for each repetition.

Look at the Dot Plot: How many times did we get a result of 58 or higher?

Based on our simulation, what is the probability that you would randomly get an average age of 58 or higher?

Probability: proportion of successes out of total trials in the long run.

If Westvaco was truly unbiased by age would you expect that they chose the people they did? Explain.

1.2 Simulation Discussion If we decided that the probability was high

enough that there was reasonable possibility that Westvaco could have chosen those employees without bias, then they may be off the hook.

However, if the probability was very low, we can say that it is very unlikely that they chose those employees unbiased of age.

They may still have valid reasoning, but now the need for an explanation is on them.

Homework Questions

P5 on page 17

E11 on page 19