Math 3 - Stats

Why do we randomly select our samples?

• to increase bias
• to reduce bias
• so we don't get the same answers from everyone
• because it's easier

Disneyland often surveys its guests as they exit a restaurant during their visit. The surveyor stands at the restaurant exit, counts the number of people leaving, and surveys every 25th guest.
This is a form of:

• Random Sample
• Convenience Sampling
• Voluntary Response
• Systematic Sampling

A teacher wants to know the average time spent doing homework by the students in her class of 20 girls and 5 boys.
She selects the first five who raise their hands.

• Systematic
• Convenience
• Voluntary Response
• Simple Random

A teacher wants to know the average time spent doing homework by the students in her class of 20 girls and 5 boys.
She selects the five closest to her desk.

• simple random
• Voluntary Response
• Convenience
• Systematic Random

An independent research company wants to go door to door to survey people in the city of Fontana. The company decides to number all blocks within the city limit, randomly choose 50 blocks and survey all households on each selected block. 
This is an example of:

• Simple Random Sample
• Stratified Random Sample
• Cluster Random Sample
• Systematic Random Sampling

A ___ is a large group that includes everything being studied.

• Sample
• Stratified Sampling Method
• Population
• Voluntary-Response

A ___ is a small portion of the population used to gather data from.

• Systematic Sampling Method
• Sample
• Population
• Bias

You want to see if fifth-grade boys or fifth-grade girls are faster at solving jigsaw puzzles. You randomly select twenty fifth-grade boys and twenty fifth-grade girls from fifth graders in your school district. You time and record how long it takes each student to solve the same jigsaw puzzle correctly.

What type of study is described?

• Survey

• Experimental Study

• Observational Study

Researchers want to determine if there is a relationship between whether or not a woman smoked during pregnancy and the birth weight of her baby. Researchers examined records for the past five years at a large hospital.

What type of study is described?

• Survey

• Experimental Study

• Observational Study

Suppose that in your health class you read two studies on the relationship between eating breakfast and success in school for elementary school children. A student decided to organize a google survey that his classmates would take at the start of class on Wednesday, asking them about their breakfast that morning.

What type of study is described?

• Survey

• Experimental Study

• Observational Study