Graphing Proportional Relationships in 8th Grade Math

The video tutorial explains how to graph a line representing a proportional relationship between y and x with a unit rate of 0.4. It covers the concept of proportional relationships, graphing points, understanding slope, and deriving the equation of a line. The tutorial uses examples to illustrate how changes in x affect y and how to calculate the slope as the rate of change. The final equation of the line is determined to be y = 0.4x.

What does a unit rate of 0.4 in a proportional relationship between y and x mean?

• A change of 0.4 units in x corresponds to a change of 1 unit in y.

• A change of 0.4 units in y corresponds to a change of 0.4 units in x.

• A change of 1 unit in x corresponds to a change of 0.4 units in y.

• A change of 1 unit in y corresponds to a change of 0.4 units in x.

In a proportional relationship, what is the value of y when x is 0?

• 0

• 0.4

• 1

• Undefined

If x increases by 1 unit, by how much does y increase in this proportional relationship?

• 0.6 units

• 0.2 units

• 0.4 units

• 1 unit

What is the y-value when x is 5 in this proportional relationship?

• 1.5

• 1

• 2.5

• 2

Which point is easy to graph and lies on the line representing this proportional relationship?

• (1, 0.4)

• (2, 0.8)

• (5, 2)

• (3, 1.2)

What is the slope of the line representing this proportional relationship?

• 0.8

• 0.4

• 0.2

• 0.6

How do you calculate the slope of a line?

• Difference between x and y

• Change in y over change in x

• Sum of x and y

• Change in x over change in y

What is the equation of the line representing this proportional relationship?

• y = 0.8x

• y = 0.6x

• y = 0.4x

• y = 0.2x

If y = 2 when x = 5, what is the constant of proportionality (k)?

• 0.6

• 0.5

• 0.4

• 0.2

What is the y-value when x is 0 according to the equation y = 0.4x?

• 2

• 1

• 0.4

• 0