At a local food processing plant, it used to take an average of 90 minutes for new workers to learn a food processing job. Recently the company installed a new food processing machine. The supervisor at the company wants to find if the mean time taken by new workers to learn the food processing procedure on this new machine is different from 90 minutes. A sample of 20 workers showed that it took, on average, 85 minutes for them to learn the food processing procedure on the new machine. It is known that the learning times for all new workers are normally distributed with a population standard deviation of 7 minutes. Use a significance level of 0.01 to test the claim that the mean time is different from 90 minutes. What is the test statistic? A) -7.01 B) -2.539 C) -3.19 D) -2.528 E) -1.96
At a local food processing plant, it used to take an average of 90 minutes for new workers to learn a food processing job. Recently the company installed a new food processing machine. The supervisor at the company wants to find if the
A) -7.01
B) -2.539
C) -3.19
D) -2.528
E) -1.96
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