An aerospace parts factory has one production line creating asingle population of fasteners; the widths of these fasteners arenormally distributed. A sample of 20 fasteners is selected from theproduction line for quality control inspection. The width of eachselcted fastener is measured; and the mean of the measured width ofselected fasteners is compared to the design value. Can the z test be used in this hypothesis test? Yes orno? An aerospace parts factory has one production line creating asingle population of fasteners; the widths of these fasteners arenormally distributed. A sample of 20 fasteners is selected from theproduction line for quality control inspection. The width of eachselcted fastener is measured; and the mean of the measured width ofselected fasteners is compared to the design value. Can the z test be used in this hypothesis test? Yes orno?
Explanation / Answer
No. Here the sample size, n = 20. Since, n < 30, we cannot use z test.