A placement exam for entrance into a math class yields a mean of 80 and a standard deviation of 10. The distribution of the scores is roughly bell-shaped. Use the empirical rule to find the percentage of scores that lie between 60 and 80.

If inflation is 6% and nominal gdp grew by 4%, then during the same period real gdp changed by a) -2% b) 2% c) 4% d) 5%

In the image, layer a is the topmost layer. layer c contains fossils from the precambrian era. layer b contains dinosaur fossils, and layer a contains fossils of mammals. which two statements are supported by this evidence? 1. mammals lived before the precambrian era. 2. dinosaurs and mammals existed in the precambrian era. 3. dinosaurs evolved after precambrian organisms. 4. precambrian organisms evolved after dinosaurs. 5. precambrian organisms were the first life-forms to become fossilized, according to this sample.

These two squirrels live in the same ecosystem. what type of interaction do the images represent? a. direct competition b. mutualism c. interference competition d. symbiotic e. indirect competition