what was the age

What was the age distribution of prehistoric Native Americans? Extensive anthropological studies in the southwestern United States gave the following information about a prehistoric extended family group of 79 members on what is now a Native American reservation. For this community, estimate the mean age expressed in years, the sample variance, and the sample standard deviation. For the class 31 and over, use 35.5 as the class midpoint. (Round your answers to one decimal place.) Age range (years 1-10 11-20 21-30 31 and over Number of individuals 34 19 16 10 X : -/2.65 Points] DETAILS BBUNDERSTAT12 3.3.001. MY NOTES ASK YOUR TEACHER Angela took a general aptitude test and scored in the 80th percentile for aptitude in accounting. (a) What percentage of the scores were at or below her score? % (b) What percentage were above? %