The mean length of 6 childrens' big finger is 8.3cm. The mean length of 5 adults' big finger is 17.7cm. What is the mean length (rounded to 2 DP) of these 11 people's big finger?

The mean for the whole group is 12.57 cm

Step-by-step explanation:

The mean of the length of each group's finger is given by the following formula:

mean = (sum of lengths from each finger) / number of people

Therefore for the first group:

8.3 = (sum1) / 6

sum1 = 8.3*6 = 49.8

For the second group:

17.7 = sum2/5

sum2 = 17.7*5 = 88.5

Therefore the mean from the whole group is:

mean = (sum1 + sum2) / 11 = (49.8 + 88.5) / 11 = 12.57 cm