the amount of water is directly proportional to the number of cups of rice. the coordinate (1/2,1) is on the graph of this proportional relationship. identify another point on the graph

a) 2,6
b) 3/2,3
c) 2/3,4
d) 1/4,2

1 answer

Given that the amount of water is directly proportional to the number of cups of rice, we can express this relationship as:

\[ W = kR \]

where:

  • \( W \) is the amount of water,
  • \( R \) is the number of cups of rice,
  • \( k \) is the constant of proportionality.

The point \((1/2, 1)\) means that when \( R = 1/2 \), \( W = 1 \). We can use this point to find the constant \( k \):

\[ 1 = k \left(\frac{1}{2}\right) \] \[ k = 2 \]

Now, the relationship can be described as:

\[ W = 2R \]

Now we can use this equation to find another point on the graph by selecting a value for \( R \) and calculating the corresponding \( W \).

Let's examine the answer choices by evaluating each one to see if they fit the equation \( W = 2R \).

a) For \( R = 2 \): \[ W = 2(2) = 4 \] The point is \( (2, 4) \), which is not among the options.

b) For \( R = 3/2 \): \[ W = 2\left(\frac{3}{2}\right) = 3 \] The point is \( (3/2, 3) \), which is one of the options.

c) For \( R = 2/3 \): \[ W = 2\left(\frac{2}{3}\right) = \frac{4}{3} \] The point is \( (2/3, 4/3) \), which is not among the options.

d) For \( R = 1/4 \): \[ W = 2\left(\frac{1}{4}\right) = \frac{1}{2} \] The point is \( (1/4, 1/2) \), which is not among the options.

Based on this analysis, the point that lies on the graph of the proportional relationship is:

b) \( (3/2, 3) \).