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### Unit 5: Lesson 3

Topic C: Random sampling and estimating population characteristics

# Reasonable samples

To make a valid conclusion, you'll need a representaive, not skewed, sample. Created by Sal Khan.

## Want to join the conversation?

• At , why would asking the whole class be less efficient? Wouldn't the class be the only relevant demographic in this case?
• u still want the answer?... its been 6 years
• I thought when using a computer to generate something random, that it's not truly random? Rather pseudo-random?
• You are right, but for the purpose of the exercise, it is random.
• So what percent of a number is reasonable. So like if there were 60,000 students in a school, is 50 students a reasonable amount of students to ask their opinions'?
• Rather than a exact percentage, the more important requirement is a random sampling, so 50 may be a reasonable amount if it is truly a random sampling. Think about a presidential race, there is no easy way to get even close to 1% of possible voters (138+ million people voted in 2016, so 1 percent is 1.3 million people, .1% is 138,000, and .01 is still 13,800 voters which is still a lot), so they have to define the parameters of who they chose as opinions.
Statistics can be misleading if it is not random such as the number of toothpaste brands that 4 out of 5 dentists recommend.
(1 vote)
• what website do you get these questions on?
(1 vote)
• A magazine asks people to visit its website to vote for Australia's most popular TV start

Why would this survey's sample be biased?
(1 vote)
• Because it is limited to
(1) People who read that magazine
• what is the difference
• what is your favorite thing you like
• Khan academy is my favorite thing i like