Find, to two decimal places, the mean of the test scores in the table. Then determine which group’s score is closest to the mean.
We have eight class groups from A to H. The test scores range from 70 to 93. The first part of this question wants us to calculate the mean. We do this by dividing the sum of the values by the number of values. We need to add 78, 86, 72, 93, 92, 84, 87, and 70. This gives us a total of 662. As there are eight class groups altogether, we need to divide 662 by eight. This gives us 82.75. The mean test score is therefore equal to 82.75.
The second part of the question asks us to work out which group is closest to this mean value. The test score that is immediately above 82.75 is 84. And the test score that is immediately below the mean is 78. As 82.75 is closer to 84 than 78, this is the correct answer. Group F score of 84 is the one that is closest to the mean.