Question

*If the average height of 20 girls in the class is 130 cm and the average height of 20 boys is 134 cm, what is the average height of all the students in the class?*

1️⃣ 132.5 cm
2️⃣ 133 cm
3️⃣ 132 cm
4️⃣ 131.5 cm​

Answer 1

Answer:

option 3) 132 cm

Step-by-step explanation:

$Average \: height \: of \: all \: students = \frac{Sum \: of \: heights \: of \: all \: students}{total \: no \: of \: students} = \frac{sum}{20 \: boys + 20 \: girls}$

Sum of heights of all students = Sum of heights of all girls + Sum of heights of all boys

= (Average height of all girls × total no. of girls) + (Average height of all boys × total no. of boys)

= (130 × 20) + (134 × 20)

= 5280

Avarage height of all students = 5280/40 = 132

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