Random Sampling and Population Inference

The video tutorial covers the concept of random sampling and its significance in making population inferences. It explains the criteria for a sample to be considered random and provides examples to distinguish between random and non-random samples. The tutorial also discusses how to use random samples to make predictions about a larger population, using a case study from Eastside Middle School. It includes calculations for percentages and predictions, evaluates true or false statements based on data, and offers homework help related to sampling.

What is a key requirement for a sample to be considered random?

• It must include only students who walk to school.

• Everyone in the population must have an equal chance of being selected.

• It must include only students who ride the bus.

• It must include only females.

Why is selecting every tenth student off the bus not a random sample?

• It includes students who walk to school.

• It only includes students who ride the bus.

• It includes students who drive to school.

• It includes students from all grades.

Which scenario represents a random sample?

• Asking students who are interested to meet in the library.

• Surveying only the choir students.

• Surveying only students who play sports.

• Selecting every 20th student on the school roster.

What is a population inference?

• A survey of all students in a school.

• A guess about a character in a book.

• A detailed analysis of a single student's preferences.

• A prediction about a larger population based on a sample.

How many students were surveyed in the elective choice example?

• 50

• 60

• 30

• 40

What percentage of the surveyed students chose Spanish as their elective?

• 35%

• 30%

• 25%

• 40%

If 6 out of 40 students chose art, how many students out of 350 are expected to choose art?

• 50

• 53

• 55

• 60

Why was Miguel incorrect in thinking art should be dropped?

• Because 6 students is more than 10% of the sample.

• Because art is not an elective.

• Because 6 students is less than 10% of the sample.

• Because art is a popular choice.

What is the correct prediction for the number of students choosing theater out of 350?

• 180

• 175

• 160

• 150

What should be ensured when taking a random sample to make predictions?

• Only select students who volunteer.

• Only select students from one class.

• Ensure everyone has an equal chance of being selected.

• Select students based on their grades.