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Which statement is true of direct proportionality? If the x variable increases b

ID: 140860 • Letter: W

Question

Which statement is true of direct proportionality?

If the x variable increases by 25%, then the y variable increases by 50%.

The graph of a directly proportional relationship is a straight line.

The graph of a directly proportional relationship may cross the y axis at any value.

The slope of a directly proportional relationship can never be less than one.

If the x variable increases by 25%, then the y variable increases by 50%.

The graph of a directly proportional relationship is a straight line.

The graph of a directly proportional relationship may cross the y axis at any value.

The slope of a directly proportional relationship can never be less than one.

Explanation / Answer

The graph of a directly proportional relationship is astraight line.

The above line is true of direct proportionality. Since the relation between linear and direct proportionality is given by the formula y= ax + b, where a is the gradient per x axis and b is the y intercept.

eg)

The difference in y row is +3 is a (gradient) per axis where as b is the y-intercept so the final equation for the above example would be y= 3x + 6 .

x 0 1 2 3 y 6 9 12 15