A store manager wants to know the percentage of shoppers who use coupons. He surveys everyone who enters the meat aisle. He finds that 60 percent of shoppers use coupons. Does the sampling method the store manager used support a valid inference?
No, because the sample is not chosen randomly.
No, because not all people who enter the meat aisle use coupons.
Yes, because the sample contains coupon users and non-users.
Yes, because the manager asked everyone who entered the meat aisle.
No, because the sample is not chosen randomly.
A quality control manager wants to determine the percentage of defective light bulbs in the production line. Which of the following sampling methods would most likely lead to a valid inference?
Random sampling, where each light bulb has an equal chance of being selected, would most likely lead to a valid inference.
A quality control manager wants to determine the percentage of defective light bulbs in the production line. Which of the following sampling methods would most likely lead to a valid inference?(1 point)
Responses
testing the first 2,000 light bulbs in the production line
testing the first 2,000 light bulbs in the production line
testing every fiftieth light bulb in the production line
testing every fiftieth light bulb in the production line
testing the last 4,000 bulbs in the production line
testing the last 4,000 bulbs in the production line
retesting 100 light bulbs that have already been tested
Testing every fiftieth light bulb in the production line, where a random starting point is chosen and every fiftieth bulb on the line is selected for testing, would most likely lead to a valid inference.
Avery randomly selects 50 colored pencils from a basket and finds that 2 are not sharpened. If the basket contains 300 colored pencils, how many would you expect to be unsharpened?(1 point)
Responses
20
20
2
2
12
12
120
You would expect approximately 12 colored pencils to be unsharpened.
To find out, you can set up a proportion:
unsharpened pencils in sample/total sample = unsharpened pencils in population/total population
Substituting the given values, 2/50 = x/300.
Solving for x:
2/50 = x/300
x = (2/50) * 300
x = 12
There are 628 students in Tan’s high school. Tan surveys 120 randomly chosen students about their favorite movie genre. The results are as follows.
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Random Sampling Quick Check
4 of 54 of 5 Items
Question
There are 628 students in Tan’s high school. Tan surveys 120 randomly chosen students about their favorite movie genre. The results are as follows.
Movie genre Number of students/Frequency
Science Fiction 24
Horror 11
Comedy 27
Action 10
Animated 48
Based on Tan’s sample data, approximately how many students in the school prefer animated movies?
(1 point)
Responses
125
125
251
251
141
141
52