Four students were discussing how to find the unit rate for a proportional relationship. which method is valid? “look at the graph of the relationship. find the y-value of the point that corresponds to x = 1. that value is the unit rate.” “look at the graph of the relationship. count the number of units up and the number of units to the right one must move to arrive at the next point on the graph. write these two numbers as a fraction.” “look at the graph of the relationship. find the x-value of the point that corresponds to y = 2. that value is the unit rate.” “look at the graph of the relationship. find two points which have y-values that are one unit apart. the unit rate is the difference in the corresponding x-values.”

 The correct answer is: [A]:

       " Look at the graph of the relationship.  Find the y-value of the point that corresponds to x = 1 .   That value is the unit rate. "

Step-by-step explanation:

Note that the "unit rate" is the term that refers to:

a "quantity" / or "quantitative value" ;  

       →  of some type of "countable units"

{e.g. "currency"  — [such as:  dollars, cents,  pounds] ; "distance/length/ width/ height" — [such as:  miles, kilometers, meters, centimeters, yards, feet, inches] ;  pieces of fruits — [such as:  number of apples;  cans of soda, number of red dresses] ;  

 per "single unit" of something — {e.g. per hour; per minute; per mile; per ounce; per hour; per dollar, per kilometer, per day, per week.

   {e.g.

             →    " 3 apples eaten  per [single] apricot eaten" ;

             →  " 46 miles per hour.

             →   " 8.3 cents per oz."  ;

             →  " 5 Liters of soda per dollar " ;

             →   " 2.3 grams per mole " ;

             →  " 4.6 mg solute / kg of solvent " ;  

             →  " 5 km / hr " ;  {that is:  " 5 km per hr " } .

             →  " 3 yds. per [single] square inch."

             →  " 35 parts per hundred" ; {that is:  " 35 percent" ; or: " 35 % " . } .

             →    " ... The cilantro is on sale for 33 cents per bundle ...} ."

   →  ... to provide a few examples.  

     On on Cartesian plane graph,  the  "x-axis" is located on the "horizontal axis" that represents the "independent variable" (or, at times, the "experimental value" — which can be manipulated — or "controlled" —or  be subjected to being "manipulated" / "controlled" / or, "selected".

   The "y-axis" is located on the "vertical axis" that represents the "dependent variable" (or, at times, the "control value") that cannot be "manipulated" / controlled/ or "selected" / since it represents the "y-value" of the corresponding coordinate to which the "x-value" happens to corresponds to at the given value for "x" .

   So, if the "unit rate" represents the "single unit rate" ;  we look at "x = 1 " ;  since we are "choosing" this particular "single" rate of per "single" (i.e. "1" ) ; so we do not have a choice in what "y-value" of the particular graph to select.  We can control the fact that we are "choosing" to find the "unit" rate, so we select the "independent variable" , "x = 1 " . We then examine the "corresponding y-value" that happens to exist when "x = 1 " .

 {Note that we have "no control" over what that "y-value" is ; at the: "[point which:  " x = 1 .] . "

→  As such, that "y-value" [insert that numeric "y-value" ;                        followed by the units represented by the "y-axis" ] ;

            per  " 1 " [insert "single unit" represented by the "x-axis" ] ;

           →   is the:  "unit rate" .

So:  

    The correct answer is:    [A]:  

     " Look at the graph of the relationship.  Find the y-value of the point that corresponds to x = 1 .   That value is the unit rate. "

Hope this answer is helpful to you!

    Best wishes to you in your academic endeavors —

            and within the "" community!

A.) “Look at the graph of the relationship. Find the y-value of the point that corresponds to x = 1. That value is the unit rate.”

Step-by-step explanation:

You have to have the y-value of the point that corresponds to x = 1. That value is the unit rate. leading to the answer A.

Have a nice day.