The following is the frequency for the speeds of a sample of automobiles traveling on tan interstate highway. Speed frequency 50-54 2 55-59 4 60-64 5 65-69 10 70-74 9 75-79 5 The mean is A.10 B. 67 C. 35 D. 670 Solution mean=(52*2+57*4+62*5+67*10+72*9+77*5)/(2+4+5+10+9+5)=67 Answer:B. 67.