Use the Normal to Model the Distribution of Sample Means

Multiple Choice

Use the Normal to model the distribution of sample means.
-In a metal fabrication process, metal rods are produced that have an average length of 20.5 feet with a standard deviation of 2.3 feet. A quality control specialist collects a
Random sample of 30 rods and measures their lengths. What is the probability of
Observing a sample mean greater than 21 feet?

A) 0.3830
B) 0.8830
C) 0.4778
D) 0.5222
E) 0.1170