Question 5 • EHS Content Recovery - Probability and Statistics - Part D
A computer company wants to determine if there is difference in the proportions of defective computer chips in a day’s production from two different production plants, A and B. A quality control specialist takes a random sample of 100 chips from the day’s production from plant A, and determines that there are 12 defective chips. The specialist then takes a random sample of 100 chips from the day’s production from plant B, and determines that there are 10 defective chips.Based on the 90% confidence interval, (–0.05, 0.09), is there convincing evidence of a difference in the true proportions of defective chips from a day’s production between the two plants?
Answer
A
There is convincing evidence because the sample proportions of defective chips for the two plants are different.
B
There is not convincing evidence because the interval contains 0.
C
There is convincing evidence because the difference in the two sample proportions is 0.02. Since this is not 0, there is a difference in the true proportions of defective chips for the two plants.
D
There is not convincing evidence because the interval contains both negative and positive values.