At a birthday party, teams for a game are chosen by putting everyone's name into a jar, and then choosing the names at random for each team.
simple random
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15
While students are lined up for school pictures, a teacher passes out a survey to every 10th student.
systematic random
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15
A pharmaceutical company wants to test the effectiveness of a new drug. Volunteers are assigned randomly to one of two groups. The first group will receive the new drug; the second group will receive a placebo.
simple random
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lifesaver
Give 15 points!
Oops!
seesaw
Swap points!
Okay!
shark
Other team loses 25 points!
Okay!
thief
Give points!
5
10
15
20
25
boom
Lose 50 points!
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star
Double points!
Okay!
shark
Other team loses 20 points!
Okay!
thief
Give points!
5
10
15
20
25
15
A restaurant leaves a fishbowl on the counter for diners to drop their business cards. Once a month, a business card is pulled out to award one lucky diner with a free meal.
simple random
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15
A student council surveysย 100 students by getting random samples ofย 25 freshmen,ย 25 sophomores,ย 25 juniors, andย 25 seniors.
stratified random
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15
A team wants to do a research on university students by sampling 30 students from each program.
stratified random
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15
A survey about timekeeping might divide the population by time zone, then take 100 random samples per zone.
stratified random
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15
The company has 800 female employees and 200 male employees so you use random sampling on each group, selecting 80 women and 20 men, which gives you a representative sample of 100 people.
stratified random
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15
A principal takes an alphabetized list of student names and picks a random starting point. Everyย 20th student is selected to take a survey.
systematic random
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15
At airport security, every 25th person gets baggage searched.
systematic random
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15
At a bingo game, balls with every possible number are placed inside a mechanical cage. The caller rotates the cage, tumbling around the balls inside. Then, she selects one of the balls at random to be called, like B-12 or O-65.