The mean length of 4 childrens' big finger is 14cm. The mean length of 9 adults' big finger is 16.1cm. What is the mean length (rounded to 2 DP) of these 13 people's big finger?
Mathematics · High School · Thu Feb 04 2021
Answered on
mean length of 4 childrens' big finger, x =
14cm
mean length of 9 adults' big finger is 16.1cm,
y= 16.1cm
Let the total length of the 4 childrens' big
finger =t
number of childrens =n
x = t/n
t = x × n
t= 4 × 14
t= 56 cm
Let the total length of the 9 adults' big
finger T
Numbe of adults = N
y =T/N
T = y × N
T= 16.1 × 9
T = 144.9
The total length of the 13 people's big finger
= t+T
= 56 +144.9
200.9 cm
The mean length of these 13 people's big
finger :
z = (200.9) / 13
z = 15.4539 cm
z = 15.45 cm
Therefore, the mean length of the 13
people's big finger is 15.45 cm.