In the graph, the constant of proportionality is 40
<h3>Calculating the constant of proportionality</h3>
From the question, we are to determine the constant of proportionality
The constant of proportionality = 
From the graph, a point on the line is (1, 40)
That is,
When x = 1 and y = 40
Thus,
The constant of proportionality = 
Constant of proportionality = 40
Hence, the constant of proportionality is 40
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