population variance? You need to determine the population variance of the diameters of a specialized electronic component you need to use for a new product. Other studies indicate that the diameters of this product are roughly normally distributed. You take a sample of 20 units and find out that the sample average diameter is 0.24 mm, and the sample standard deviation is 0.2 mm. What is the 90% confidence interval for the (0.025,0.075) (0.125 ,0.175) (1.125, 1.175) (1.125, 2,362) (1.125, 3.362)