One of the most important aspects of quality improvement is the idea of reducing the variability in a product or service. For instance, a major bank has worked to reduce the variability in the service time at the drive-through. The managers believe that the standard deviation in service time should not exceed 30 seconds. To test whether this goal is being achieved, a random sample of n = 25 cars is selected each week and the service time for each car is measured. Last week, the mean time was 345 seconds with a standard deviation equal to 38 seconds. Given this information, if the significance level is 0.10, the critical value from the chi-square table is about 34.3.

Question

Quizplus · Accepted Answer

The critical value from the chi-square table for a given significance level and degrees of freedom (which in this case would be n-1 = 24 for a sample size of 25) is not specified in the question. The value of 34.3 mentioned does not directly relate to the significance level without specifying the degrees of freedom and whether it's a one-tailed or two-tailed test. Chi-square critical values depend on the degrees of freedom and the significance level, and without this specific information, the exact critical value cannot be determined.

One of the Most Important Aspects of Quality Improvement Is