Total juice boxes = 3 + 1 + 2 + 4 = 10
probability first one out is grape = 2 / 10
probablility second one out is grape 1 / 9 (one taken already and only nine left)
total probability = 2 / 10 x 1 / 9 = 2 / 90 = 1 / 45
To calculate the average, we will use the following rule:
average = sum of scores / number of scores
sum of scores = 85+72+89+90 = 336
number of scores = 4
average = 336/4 = 84%
