A computer company wants to determine if there is a difference in the proportion 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 first hour of production from plant A and determines that there are 12 defective chips. The specialist then takes a random sample of 100 chips from the last hour of production from plant B and determines that there are 10 defective chips. Assuming conditions for inference are met, what is the 90% confidence interval for the true difference in proportions of defective chips from a day’s production between the two plants? Find the z-table here.