7. Archaeology: Excavations The Wind Mountain archaeological site is located in southwestern New Mexico. Wind Mountain was home to an ancient culture of prehistoric Native Americans called Anasazi. A random sample of excavations at Wind Mountain gave the following depths (in centimeters)

from present-day surface grade to the location of significant archaeological artifacts (Source: Mimbres Mogollon Archaeology, by A. Woosley and A.

McIntyre, University of New Mexico Press).

85 45 120 80 75 55 65 60 65 95 90 70 75 65 68

(a) Use a calculator with mean and sample standard deviation keys to verify that x < 74.2 cm and s < 18.3 cm.

(b) Compute a 95% confidence interval for the mean depth m at which archaeological artifacts from the Wind Mountain excavation site can be found.