# Question

A machine at Katz Steel Corporation makes 3-inch-long nails. The probability distribution of the lengths of these nails is normal with a mean of 3 inches and a standard deviation of .1 inch. The quality control inspector takes a sample of 25 nails once a week and calculates the mean length of these nails. If the mean of this sample is either less than 2.95 inches or greater than 3.05 inches, the inspector concludes that the machine needs an adjustment. What is the probability that based on a sample of 25 nails, the inspector will conclude that the machine needs an adjustment?

## Answer to relevant Questions

Using the formulas of Section 5.3 of Chapter 5 for the mean and standard deviation of a discrete random variable, verify that the mean and standard deviation for the population probability distribution of Table 7.2 are 80.60 ...A population of N = 1400 has a population proportion equal to .47. In each of the following cases, which formula will you use to calculate σp̂ and why? Using the appropriate formula, calculate σp̂ for each of these ...According to a poll, 55% of Americans do not know that GOP stands for Grand Old Party (Time, October 17, 2011). Assume that this percentage is true for the current population of Americans. Let p̂ be the proportion in a ...A survey of all medium- and large-sized corporations showed that 64% of them offer retirement plans to their employees. Let p̂ be the proportion in a random sample of 50 such corporations that offer retirement plans to ...Refer to Exercise 7.94. The current distribution of all monthly cable bills in the United States is approximately normal with a mean of $82.69 and a standard deviation of $11.17. Find the probability that the average monthly ...Post your question

0