Test 7 Section 4 #37
The trick here is understanding the data in the chart. The chart shows you how many people scored each score on each day. To calculate the mean (AKA average) score on Day 1, we need to know the sum of all scores on Day 1 and the number of scores. The chart tells us the number of scores: 20 contestants played. In order to calculate the sum, we need to add up all the scores we know about.
Reading across the row for Day 1: two people got a score of 5, three people got a score of 4, four people got a score of 3, six people got a score of 2, two people got a score of 1, and three people got a score of 0. So the sum of all scores should be:
2(5) + 3(4) + 4(3) + 6(2) + 2(1) + 3(0) = 48
If the sum of scores was 48 and there were 20 contestants, then the mean score for the day was 48/20 = 2.4.