Answer:
1.54
Step-by-step explanation:
First, we can take into account that mean = sum / number of students. Therefore, we can find the sum of each group of students, as
1.67 = sum / 20
1.50 = sum / 16
1.40 = sum / 14
Multiplying each equation by the number of students in the group to isolate the sum, we get
1.67 * 20 = 33.4
1.50 * 16 = 24
1.40 * 14 = 19.6
We can sum these up to get the total sum of all three groups of students, resulting in
33.4 + 24 + 19.6 = 77
As mean = sum / number of students, we can say that
total mean = total sum / total number of students
total mean = 77 / (20+16+14)
= 77/50
= 1.54
