Answer to Question #249136 in Statistics and Probability for Jenelle

Question

Below are the number of individuals in each department

Department

Numbers

Accounts

18

Marketing

24

Sales

43

Repairs

35

How many employees from the Marketing department should Caitlyn select to be part of the sample? [2]

v. Another employee suggested that Caitlyn should group employees by the type of car they own. State a reason why grouping the employees in this way will NOT be appropriate to select this sample using the sampling method in ii

Answer 1

Caitlyn has to determine how many of the 120 employees in her work place has comprehensive car insurance. She wants to obtain a sample of 40 employees. She selections employees from each department in proportion to the number of individuals the departments.

$18x+24x+43x+35x=40$

$120x=40$

$x=1/3$

The number of employees from the Marketing department for the sample:

$24\cdot1/3=8$

v)

In previous example each individual is chosen entirely by chance and each member of the population has an equal chance, or probability, of being selected.

In the given example the population must divided into subgroups who all share a similar characteristic ( the type of car).