Question

If the mean heights of three groups of students consisting of 20,16 and 14 students are 167m, 150m and 1.40m respectively find the mean height of all the student. ​

Answer 1

The heights should be

• 1.67m,1.5m,1.4m as it's looking general and possible

Find mean

$\\ \rm\Rrightarrow Mean=\dfrac{1.67(20)+1.5(16)+1.4(14)}{14+16+20}$

$\\ \rm\Rrightarrow Mean=\dfrac{77}{50}$

$\\ \rm\Rrightarrow Mean=1.54m$

Answer 2

Answer:

1.54 m

Step-by-step explanation:

Given information:

Three groups of students

• 20 students with a height of 1.67 m
• 16 students with a height of 1.50 m
• 14 students with a height of  1.40 m

⇒ Total number of students = 20 + 16 + 14 = 50

To find the mean height of all the students, divide the sum of all the students' heights by the total number of students:

$\begin{aligned}\implies \sf mean\:height & =\dfrac{(20 \times 1.67)+(16 \times 1.50)+(14 \times 1.40)}{50}\\\\ & = \dfrac{33.4+24+19.6}{50}\\\\ & = \dfrac{77}{50}\\\\ & = 1.54\:\: \sf m\end{aligned}$

Therefore, the mean height of all the students is 1.54 m