Best Sampling Methods

The quality inspector takes every 125th component and checks it for defects. What kind of sample is this?

• Simple Random

• Convenience

• Stratified

• Systematic

• Cluster

A housekeeper checks 3 rooms at random from each of the cleaners' areas of responsibility. What kind of sample?

• Simple Random

• Convenience

• Stratified

• Systematic

• Cluster

A researcher asked every person wearing red who walked past the booth. What kind of sample is this?

• Simple Random

• Convenience

• Stratified

• Systematic

• Cluster

Assign each car in a dealership a number and then use a random-number table to select the cars to be inspected.

• systematic

• simple random sample

• convenience

• Self - selected (volunteer)

Units of the population are ordered in some fashion.  Usually, every k-th unit is chosen.

• proportional

• probable

• stratified

• systematic

Interview every 10th student who enters the school in the morning.

• simple random

• voluntary response

• systematic

• convenience

A teacher wants to know how well her students are doing on a topic. She randomly picks one class to survey.

• Simple Random

• Cluster

• Stratified

• Systematic

This sample is selected by dividing the population into subgroups and then taking a fixed number of units from each group using the simple random sample.

• stratified

• cluster

• judgment

• experimental

Units of the population are grouped; one or more groups are selected at random.  All units of that group are included in the sample.

• cluster sample

• simple random

• stratified

• proportional