For samples of the specified size from the population described, find the mean and standard deviation of the sample mean . The National Weather Service keeps records of snowfall in mountain ranges. Records indicate that in a certain range, the annual snowfall has a mean of 82 inches and a standard deviation of 12 inches. Suppose the snowfalls are sampled during randomly picked years. For samples of size 36, determine the mean and standard deviation of

How do i make someone brainliest? (if you answer me, i might be able to make you brainliest! )

Dexter read 11 science fiction books and 5 history books. lena read 9 science fiction books and 4 history books. compare the students’ ratios of science fiction books to history books. 1. determine the ratios’ form:    science fiction books to history books 2. write the ratios as fractions:    dexter: 115; lena: 94 3. rewrite with a common denominator. 4. compare. 5. answer the question. determine which shows the correct comparison of the ratios for this problem.

Atrain leaves little? rock, arkansas, and travels north at 90 kilometers per hour. another train leaves at the same time and travels south at 80 kilometers per hour. how long will it take before they are 680 kilometers? apart?