A contract calls for the strength of a steel rod to stand up to pressure of 200 lbs per square inch on average.The contract also requires that the variability in strength for individual steel rods be no more than 5 pounds per square inch.If a random sample of n = 15 rod is selected and the sample standard deviation is 6.7 pounds,the test statistic is approximately χ² = 25.138.

Question

Quizplus · Accepted Answer

The chi-square statistic is calculated as (n-1) * (s^2 / σ^2), where n is the sample size, s is the sample standard deviation, and σ is the population standard deviation. In this case, n = 15, s = 6.7, and σ = 5. Plugging these values into the formula, we get χ^2 = (15-1) * (6.7^2 / 5^2) = 25.138.

A Contract Calls for the Strength of a Steel Rod