Suppose the mean height in inches of all 9th-grade students at one high school is estimated. The population standard deviation is 6 inches. The heights of 7 randomly selected students are 73 ,70 ,61 ,75 ,60 , 60 and 67 . =

Margin of error at 90% confidence level =

90% confidence interval = [

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

Afarmer began a new method of reducing grain spills. this reduced the number of mice on the farm. the number of snakes in the surrounding area decreased at the same time. the snakes depended on the mice that lived in the field. what’s the likely reason the snake population decreased? a. the number of snake predators increased. b. the number of mice increased. c. the number of mice decreased. d. the pesticides affected the snakes. e. a new breed of mice moved into the field.

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