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 83 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.)

Scientists observed a rock stratum and discovered some fossils. the image shows the fossils they discovered. what can you interpret from the image? an illustration showing layers rock with fossils embedded in some rock layers1. the dinosaur and the mammoth existed after the trilobites.2. the dinosaur and the armored fish existed before the trilobites.3. the trilobites and the armored fish died before the dinosaur.4. the trilobites and the armored fish were born after the dinosaur.5. the early mammoth is older than the trilobites.

Carbon dioxide can be produced form what type of power generation?

Many students are as or more stressed out than their adult parents/guardians. do you believe this is true or not? use evidence from the article to answer this question is claim-evidence-reasoning format.