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. Which of the following statements is true?
A) The sampling distribution for the sample mean follows the t-distribution with 16
Degrees of freedom.
B) The sampling distribution for the sample mean follows the t-distribution with 15
Degrees of freedom.
C) The mean of the sampling distribution for the sample mean is 14.8 feet.
D) The sampling distribution for the sample mean is Normal with a mean of 14.8 feet
And standard deviation of .65 feet.
E) The standard error is 0.65 feet.

Question

Quizplus · Accepted Answer

The sampling distribution for the sample mean follows the t-distribution with 15 degrees of freedom because the sample size is 16, and degrees of freedom for a t-distribution is calculated as n-1, where n is the sample size.

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