# Question: The diameter of bushings turned out by a manufacturing process

The diameter of bushings turned out by a manufacturing process is a normally distributed random variable with a mean of 4.035 mm and a standard deviation of 0.005 mm. A sample of 25 bushings is taken once an hour.

(a) Within what interval should 95 percent of the bushing diameters fall?

(b) Within what interval should 95 percent of the sample means fall?

(c) What conclusion would you reach if you saw a sample mean of 4.020? A sample mean of 4.055?

(a) Within what interval should 95 percent of the bushing diameters fall?

(b) Within what interval should 95 percent of the sample means fall?

(c) What conclusion would you reach if you saw a sample mean of 4.020? A sample mean of 4.055?

## Answer to relevant Questions

What sample size would be required to estimate the true proportion of American female business executives who prefer the title "Ms.," with an error of ±0.025 and 98 percent confidence? Inspection of a random sample of 19 aircraft showed that 15 needed repairs to x a wiring problem that might compromise safety. How large a sample would be needed to estimate the true proportion of jets with the wiring ...A random sample of 21 nickels measured with a very accurate micrometer showed a mean diameter of 0.834343 inch with a standard deviation of 0.001886 inch. (a) Why would nickel diameters vary? (b) Construct a 99 percent ...Twenty-one warranty repairs were selected from a population of 126 by selecting every sixth item. The population consisted of "loose, not attached" minivan electrical wires (one of several electrical failure categories the ...In a sample of 100 Planter's Mixed Nuts, 19 were found to be almonds. (a) Construct a 90 percent confidence interval for the true proportion of almonds. (b) May normality be assumed? Explain. (c) What sample size would be ...Post your question