Unknown to a quality assurance technician, the tensile strengths (in pounds per square inch, psi) for all 500 heavy-duty construction bolts in a recent shipment are as listed in file XR04074. Because a bolt must be broken to measure its strength, the testing process is destructive. The technician plans to collect a simple random sample of 20 bolts, then mea sure how much tension each one withstands before it breaks. Generate the simple random sample and compute its mean breaking strength. Assuming that the bolt manufacturer has advertised that, on average, such bolts will withstand 10,000 psi, refer to your sample result in commenting on the manufacturer’s claim. (We will discuss the use of sample data in evaluating claims in much greater detail in Chapter 10, Hypothesis Testing.)
A computer and statistical software capable of selecting simple random samples.