The assumption of normality appears reasonable. This is evident by the fact that the data falls along a straight line. Yes, however, machine 2 has greater variability. Note the difference in horizontal scales. The variability between parts is greatly reduced.
Normality still looks reasonable.
The assumption of normality appears to be reasonable. This is evident by the fact that the data fall along a straight line. 9 and . Let X denote the number of defective chips in the lot. Let X denote the number of original components that fail during the useful life of the product.