The average on a history exam (scored out of 100 points) was 85, with a standard deviation of 15.

Find an equation in standard form of the parabola that passes through (-2, 9), (-4, 5), and (1, 0)

In an ecosystem, marsh snails feed on phytoplankton and painted turtles feed on marsh snails. pollution has resulted in the depletion of phytoplankton. what effect would this situation likely have on the population of marsh snails and painted turtles? as phytoplankton were destroyed, the population of marsh snails would most likely then the population of painted turtles would mostly likely a. 1. increase 2. decrease 3. stay the same b. 1. increase 2. decrease 3. stay the same

On a test the graders have a mean of 77 and a standard deviation of 8. if we can approximate the distribution of these graders by a number distribution what percent of the students. a) scores higher than 77? b) should pass the test (grades > 60)? c) should fail the test (grades < 60)?