Answer:
3000 bags
Step-by-step explanation:
In this case we must apply the formula of the mean, which would be the sum of the values divided by the amount of data is the mean:
m = (a1 + a2 ... an) / n
In this case we know the mean, we must know the 1987 data, therefore:
Let x be the number of bags sold in 1987, replacing in the previous equation:
2100 = (1800 + 1500 + x) / 3
2100 * 3 = 3300 + x
x = 6300 - 3300
x = 3000
Therefore, for the average to be a total of 2100 bags in those 3 years, the amount of bag sold in 1987 must have been 3000 bags
