1. Identify the population in each situation:
a) Generally, girls learn to walk before boys do.
b) The mean mark on yesterday's test was 72%.
c) Most food stores charge more for cream than for milk.
d) Today's teenagers prefer comfort over style.
2. A psychologist is studying the sleep patterns of the 3960 students at her university. She decides to start by asking a random sample of 30 students how many hours of sleep they get on weekday nights. Identify the type of sample in each of the following survey methods.
a. The psychologist assigns each student a number from 0001 to 3960 and uses a computer to randomly generate a list of 30 numbers to select the students for the sample.
b. Students are listed by the neighborhood they live in. The psychologist randomly selects six neighborhoods and then randomly selects five students from each one.
c. An equal proportion of students are randomly selected from each discipline.
3. Identify the sampling method: simple random, cluster, stratified, convenience, or systematic.
1. Every fifth person boarding a plane is searched thoroughly.
2. At a local community college, five math classes are randomly selected out of 20 and all of the students from each class are interviewed.
3. A researcher randomly selects and interviews fifty male and fifty female teachers.
4. A researcher for an airline interviews all of the passengers on five randomly selected flights.
5. A community college student interviews the first 100 students to enter the building to determine the percentage of students that own a car.
6. A market researcher randomly selects 200 drivers under 35 years of age and 100 drivers over 35 years of age.
7. To avoid working late, the quality control manager inspects the last 10 items produced that day.
8. The names of 70 contestants are written on 70 cards. The cards are placed in a bag, and three names are picked from the bag.
9. To ensure customer satisfaction, every 35th phone call received by customer service will be monitored.
10. A pregnancy study in Chicago randomly selected 25 communities from the metropolitan area, then interviewed all pregnant women in these communities.