A paint manufacturer fills cans of paint using a machine that has been calibrated to fill the cans to contain an average $\mu$ of 1 gallon (128 ounces) each. To test whether their machine has come out of calibration, the manufacturer takes a random sample of 25 cans and finds that they average 128.2 ounces with a standard deviation of 2 ounces. Is this strong evidence that the filling machine is set too high and thus is no longer calibrated properly?
What is the value of the standardized test statistic for this significance test?
A) -0.02.
B) 0.02.
C) 0.5.
D) -1.918.

Question

Quizplus · Accepted Answer

The standardized test statistic (z) is calculated using the formula: z = (X̄ - μ) / (σ/√n), where X̄ is the sample mean, μ is the population mean, σ is the sample standard deviation, and n is the sample size. Substituting the given values: z = (128.2 - 128) / (2/√25) = 0.5.

A Paint Manufacturer Fills Cans of Paint Using a Machine μ\muμ

A Paint Manufacturer Fills Cans of Paint Using a Machine $\mu$