Random Sampling

The video tutorial covers how to determine if a survey is representative of a population, focusing on random and unbiased samples. It explains key vocabulary such as population, random sample, and unbiased sample. Through real-world examples, it demonstrates how to identify populations and samples, and how to use survey data to make inferences and predictions. The tutorial also guides on selecting the best random sample and applying proportional relationships to predict outcomes.

What is a random sample?

• A sample that is biased

• A sample where every entry has an equal chance of being selected

• A sample chosen by the teacher

• A sample that includes only the first few entries

Why is it important for a sample to be unbiased?

• To ensure it includes only the most popular students

• To make sure it is fair and representative of the whole population

• To focus on a specific group of students

• To reduce the number of students surveyed

What does an unbiased sample ensure in survey data?

• It includes only students from one grade

• It is chosen by the principal

• It is impartial and fair

• It includes only students who like sports

In the Central Middle School example, what is the population?

• The teachers at the school

• The 55 students who like math

• The 923 students at the school

• The 180 students surveyed

Why is surveying every third student in the lunch line considered a good random sample?

• It includes only students who like sports

• It is not representative of the whole school

• It is random and includes a variety of students

• It surveys all students in the school

Which survey method is most representative for determining lunch preferences?

• Every fifth student who arrives by car

• 5 random students from every band class

• 3 random students from every homeroom

• Every grade eight student during lunch

What is the purpose of setting up a proportion in survey analysis?

• To determine the exact number of students surveyed

• To predict outcomes for the entire population

• To eliminate bias from the survey

• To select a new random sample

In the class project preference example, how many students preferred to work as a group?

• 9 students

• 16 students

• 25 students

• 375 students

How many students out of 2976 are predicted to prefer an ice cream truck?

• 119 students

• 150 students

• 2976 students

• 2361 students

What is the main goal of using survey data in predictions?

• To eliminate the need for further surveys

• To find the exact number of students who like a specific option

• To make informed predictions about the preferences of the entire population

• To ensure every student is surveyed