Unit 3 Day 5 Warm-Up

Unit 3 Day 5 Warm-Up

"Bad"/"Biased" Sampling Methods

• Convenience Sampling - select individuals rom the population who are easy to reach.

• Voluntary Response Sampling - allows people to choose to be in the sample by responding to a general invitation

"Good" Sampling = Random Sampling

Random sampling involves using chance to determine which members of a population are included in the sample.

Multiple Choice

Dylan wants to know how the students at his school rate the cafeteria. He surveyed his school's basketball team to rate the school cafeteria. Is this a biased sample of the school's population?

• Yes, because it is a convenience survey

• No, the basketball team has the smartest students

• Yes, because it's voluntary survey

• No, he should have asked the football team

Multiple Choice

Ana wants to know the average student’s opinion of the tardy policy at her school. Which group of students should she survey in order to achieve the most accurate results?

• thirty students who are often tardy
• thirty students who are rarely tardy
• thirty of her friends
• thirty randomly selected students from her school

Multiple Choice

True or False: all samples lead to a good prediction about an entire population.

• True
• False

Multiple Choice

Unbiased sampling is:

• when you choose the group you think will give you the answer you want, accept volunteers or survey by convenience
• when any member of the population is equally likely to be chosen for the sample

Multiple Choice

A school randomly chose ten English teachers and asked them which type of juice their students would prefer. Which reason best shows why this sample is biased?

• The sample didn't include students.
• The sample is too small.
• The sample can only be accurate if each teacher is included in the sample

Multiple Choice

In order to use samples to estimate something from the population, the sample should be _________________ the population.

• exactly the same as
• nothing like
• representative of
• larger than

Random Sampling Methods

• Simple Random Sample "SRS": "hat method" = every group of n individuals in the population has an equal chance of being selected as the sample.

• Stratified Random Sample: First create "strata" which are groups of individuals in the population who share a characteristic thought to be associated with the variables being study. Then, select a SRS from each stratum and combine the SRS's into one overall sample.

• Cluster Random Sample: Randomly select clusters and then gather data from ALL individuals in those clusters.

• Systematic Random Sample: Randomly select one of the first k individuls and then choose every kth thereafter.

Multiple Choice

A teacher splits her classes up by period. She then randomly picks 3 students from each period to do a survey.

• Stratified.

• Systematic

• Cluster

• Biased.

Multiple Choice

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

• Systematic Sampling Method
• Sample
• Population
• Bias

Multiple Choice

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

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

Multiple Choice

A teacher hands out an index card and asks ALL of her students to write down the following information: age, height (in inches), and what grade they are in.

Which of the following best describes her method of data collection?

• Census

• Simple Random Sample

• Cluster Random Sample

• Stratified Random Sample

Multiple Choice

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 1 block and survey all households on that block.

This is an example of:

• Simple Random Sample

• Stratified Random Sample

• Cluster Random Sample

• Systematic Random Sampling

Multiple Choice

Marianne wanted to know students' opinion on the new schedule at school. She survey's the first 30 students who come into her class.

• Convenience Sampling

• Systematic Random Sampling

• Simple Random Sampling

• Volunteer response

Multiple Choice

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)

Multiple Choice

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

• simple random

• voluntary response

• systematic

• convenience