You read a journal article in which the researcher compares two existing third grade classrooms, one using a new behavioral management approach and the other using the usual approach. The researcher did not randomly assign the approach. What type of design is this study

Asocial networking site currently has 400,000 active members, and that figure is predicted to increase by 32% each year. the following expression represents the number of active members on the site after t years.

The median of a data set is the measure of center that is found by adding the data values and dividing the total by the number of data values that is the value that occurs with the greatest frequency that is the value midway between the maximum and minimum values in the original data set that is the middle value when the original data values are arranged in order of increasing (or decreasing) magnitude

Which of the following is the shape of a cross section of the figure shown below