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 n-1 degrees of freedom, where n is the sample size. Here, n = 16, so the degrees of freedom is 15.

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