Averages
Commercial arithmetic · Mathematics
Study notes
Q: Scores: 78, 85, 92, 88, 77. Find mean. A 6th score of 90 is added; new mean? Step 1: Sum = 78 + 85 + 92 + 88 + 77 = 420. Step 2: Mean = 420/5 = 84. Step 3: New sum = 420 + 90 = 510. New mean = 510/6 = 85.