Psychology and Human Behavior
The Great Wall of China was started in 214 b.c. and designed as a defense against nomadic tribes. This 1500-mile-long wall, built from earth and stone, is visible from space and is one of the most famous structures in the world. Suppose a random sample of midpoints between guard towers along the Great Wall was obtained, and the height of the wall at each point was measured (in feet). The data are given in the following table.
a. Find a 95% confidence interval for the population variance in height at the midpoints between guard towers of the Great Wall.
b. Using the confidence interval constructed in part (a), is there any evidence to suggest the true population variance in the height at midpoints between guard towers is less than 12 feet? Justify your answer.