EXAMPLE 5.5 The Probability of Nonconforming Switches

CASE 5.1 The quality engineer in Case 5.1 inspects an SRS of 150 switches from a large shipment of which 8% fail to conform to specifications. What is the probability that exactly 10 switches in the sample fail inspection? What is the probability that the quality engineer finds no more than 10 nonconforming switches? Figure 5.1 shows the output from one statistical software system. You see from the output that the count has the distribution and

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It was easy to request these calculations in the software’s menus. Typically, the output supplies more decimal places than we need and sometimes uses labels that may not be helpful (for example, “Probability Density Function” when the distribution is discrete, not continuous). But, as usual with software, we can ignore distractions and find the results we need.