Question

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?

A- testing the first 2,000 light bulbs in the production line
B- testing every fiftieth light bulb in the production line
C- retesting 100 light bulbs that have already been tested
D -testing the last 4,000 bulbs in the production line

Answer 1

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?

A 20
B 120
C 2
D 12

Answer 2

B- testing every fiftieth light bulb in the production line. This is a form of systematic sampling, where every Nth item is selected for testing. It ensures that the sample is representative of the population and reduces the likelihood of bias or non-representativeness. The other sampling methods may introduce biases or may not be representative of the entire production line.