Algebra

A class of 30 students recently took a test. If 20 students scored 80, 8 students scored 90, and 2 students scored 95, then what was the class average (the mean) on this test?    

                                                       20 x 80  = 1600    

                                                         8 x 90  =   720    

                                                         2 x 95  =   190    

add them up                                                    2510    

                                                    2510 / 30  =  83.67    

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