Unit 3

A factory has 20 assembly producing a popular toy. To inspect a representative sample of 100 toys, quality control staff randomly selected 5 toys from each lines output. was this a simple random sample?

• Yes, because the toys were selected at random

• Yes, because the toys were selected at random

• Yes, because a stratified sample is a type of simple random sample

• No, because not all combinations of 100 toys could have been chosen

• No, because the toys o not come off the assembly line at random

Which is the sampling technique?

Place an announcement in the newspaper asking people to call their council representatives to register their opinions. Council members will tally calls they receive.

• voluntary response

• cluster

• convenience

• stratified

Which is the sampling technique?

Have each council member survey 50 friends, neighbors, or co-workers

• cluster

• stratified

• convenience

• systematic

Which is the sampling technique?

Have the Board of Elections assign each voter a number, then select 400 of them using a random number table

• cluster

• systematic

• stratified

• simple random sample

Which is the sampling technique?

Randomly pick 50 voters from each election district

• simple random sample

• stratified

• cluster

• systematic

Which is the sampling technique?

Call every 500th person in the phone book

• systematic

• simple random sample

• convenience

• cluster

Which is the sampling technique?

Randomly select several city blocks, interview all the adults living on the block

• systematic

• simple random sample

• stratified

• cluster

Marketing researchers wonder if the color and type of candy's packaging may influence sales of candy.

They manufacture test packages for chocolate mints in 3 colors (white, green, and silver) and 3 types (box, bag, and roll).

Suspecting that sales may depend on a combination of package and color and type, the researchers prepare nine different packages, then market them for several weeks.

How many factors?

• 2

• 9

• 3

• 6

Marketing researchers wonder if the color and type of candy's packaging may influence sales of candy.

They manufacture test packages for chocolate mints in 3 colors (white, green, and silver) and 3 types (box, bag, and roll).

Suspecting that sales may depend on a combination of package and color and type, the researchers prepare nine different packages, then market them for several weeks.

What are the experimental units? ​ ​ ​ (a)  

• candy packages
• colors
• types
• reserachers

Marketing researchers wonder if the color and type of candy's packaging may influence sales of candy.

They manufacture test packages for chocolate mints in 3 colors (white, green, and silver) and 3 types (box, bag, and roll).

Suspecting that sales may depend on a combination of package and color and type, the researchers prepare nine different packages, then market them for several weeks.

How many treatments are there?

• 2

• 6

• 9

• 3