The graph that shows the proportional relationship y = 0.7x is Graph A.
What is a proportional relationship?
A proportional relationship is a function in which the output variable is given by the input variable multiplied by a constant of proportionality, that is:
y = kx
In which k is the constant of proportionality.
In this problem, 7 out of 10 customers preferred the restaurants new spaghetti sauce, hence the constant is given by:
k = 7/10 = 0.7.
And the equation is:
y = 0.7x.
When x = 0, y = 0, which already eliminates graphs C and D. When x = 10, y = 7, which means that Graph A is the answer to this question.
More can be learned about proportional relationships at https://brainly.com/question/10424180
