The median of a data set is
a. the most commonly occurring data point in a data set
b. the arithmetic average of the data points in a data set
c. the middle point of a data set arranged in increasing order
d. the difference between the greatest and least data points in the data set

Lance lived in portugal and brazil for a total of 14 months to learn portuguese. he learned an average of 130 new words per month when he lived in portugal, and an average of 150 new words per month when he lived in brazil. in total he learned 1920 new words. write a system of equations to represent the situation. use x to represent portugal, and y to represent brazil

Find the solution of this system of equation -7x+y=-20 9x-3y=36

Perry observes the opposite parallel walls of a room in how many lines do the plains containing the walls intersect