Answer:
The girl was 144cm tall
Step-by-step explanation:
Total height of the three boys=3×156=468
Total height of the four children=4×153=612
Height of the girl=612-468=144cm
The average height of 3 boys was 156cm. Therefore, The girl was 144cm tall.
Let the thing that is changing be y and the thing with which the rate is being compared is x, then we have the average rate of change of y as x changes as:
[tex]\text{Average rate} = \dfrac{y_2 - y_1}{x_2 - x_1}[/tex]
The average height of 3 boys was 156cm.
When a girl joined them, the average height of the 4 children was 153cm.
Total height of the three boys = 3 × 156 = 468
Total height of the four children = 4 × 153 = 612
Height of the girl = 612 - 468 = 144cm
Hence, the girl was 144cm tall.
Learn more about average here:
https://brainly.com/question/12322912
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