A toy manufacturer wants to know how many new toys children buy each year. Assume a previous study found the variance to be 2.25. He thinks the mean is 7.2 toys per year. What is the minimum sample size required to ensure that the estimate has an error of at most 0.12 at the 95% level of confidence

Find and simplify an expression for the area of five rows of x squares with side lengths of x centimeters .

Drag and drop the answers into the boxes to complete this informal argument explaining how to derive the formula for the volume of a cone. since the volume of a cone is part of the volume of a cylinder with the same base and height, find the volume of a cylinder first. the base of a cylinder is a circle. the area of the base of a cylinder is , where r represents the radius. the volume of a cylinder can be described as slices of the base stacked upon each other. so, the volume of the cylinder can be found by multiplying the area of the circle by the height h of the cylinder. the volume of a cone is of the volume of a cylinder. therefore, the formula for the volume of a cone is 1/3 1/2 1/3πr^2h 1/2πr^2h πr^2h πr^2

Aproduction manager test 10 toothbrushes and finds that their mean lifetime is 450 hours. she then design sales package of this type of toothbrush. it states that the customers can expect the toothbrush to last approximately 460 hours. this is an example of what phase of inferential statistics