Two variables that move in the same direction in the same proportion. In other words, they increase and decrease together in the same proportion.
Two variables that move in the same direction in the same proportion are said to have a positive correlation.
The relationship you are describing is known as a direct proportion or a positive correlation. When two variables have a direct proportion, it means that an increase in one variable corresponds to an increase in the other variable, and a decrease in one variable corresponds to a decrease in the other variable. The relationship can be expressed mathematically as:
y = kx
where y and x are the variables, and k is a constant known as the proportionality constant.
The concept you are referring to is called "direct proportionality" or "direct variation." Two variables are said to be directly proportional or vary directly if they change in the same direction and at a constant ratio to each other. This means that as one variable increases, the other variable also increases, and as one variable decreases, the other variable also decreases.
To understand whether two variables are directly proportional, you can follow these steps:
Step 1: Examine the given data or information related to the variables in question. Look for patterns or relationships between the values of the variables.
Step 2: Create a table or chart to organize the values of the variables and observe how they change.
Step 3: Calculate the ratio between the values of the variables. Divide corresponding values of one variable by the corresponding values of the other variable. If the ratios remain constant, regardless of the values chosen, the variables are directly proportional.
Step 4: Construct a graph with the variables as the x-axis and y-axis. Plot the data points you have, and if the graph forms a straight line passing through the origin (0,0), the variables are directly proportional.
Step 5: Check if the statement holds true for any other values outside of those provided. If the variables maintain the same ratio as observed previously, they can be considered directly proportional.
By following these steps of observation, calculation, and analysis, you can determine whether two variables are directly proportional to each other.