In a metal fabrication process, metal rods are produced to a specified target length of 15 feet. Suppose that the lengths are normally distributed. A quality control specialist
Collects a random sample of 16 rods and finds the sample mean length to be 14.8 feet and
A standard deviation of 0.65 feet. The standard error of the mean is
A) 0.65 ft.
B) 0.346 ft.
C) 0.1625 ft.
D) 0.0098 ft.
E) 1.625 ft.

Question

Quizplus · Accepted Answer

The standard error of the mean (SEM) is calculated by dividing the standard deviation by the square root of the sample size: SEM = σ/√n. Here, σ = 0.65 feet and n = 16. Thus, SEM = 0.65 / √16 = 0.65 / 4 = 0.1625 feet.

In a Metal Fabrication Process, Metal Rods Are Produced to a Specified