What is a trend line
http://www.mathsisfun.com/definitions/trend-line.html
On a trend line I'm doing, it passes through the ordered pairs 1,30 1.5,50 and 3,100. For each one I get a different equation so which one do I use
A trend line is a straight line on a graph that represents the general direction or pattern of a set of data points. It is used to visually represent the relationship between two variables and to identify any possible trends or patterns in the data.
To calculate and draw a trend line, you typically need a set of data points that represent the values of the variables you are studying. Here's a step-by-step guide on how to create a trend line:
1. Collect Data: Gather the data points for the variables you want to analyze. Make sure you have enough data points for a meaningful interpretation.
2. Plot Data Points: Plot the data pairs on a scatter plot, with one variable on the x-axis and the other on the y-axis.
3. Determine the Line Equation: Use mathematical techniques, such as linear regression, to find the equation that best fits the data points. This equation represents the trend line.
4. Calculate Slope and Intercept: From the line equation, determine the slope (the rate of change between the variables) and the y-intercept (the value of the dependent variable when the independent variable is zero).
5. Draw the Trend Line: Using the slope and intercept values, draw a straight line that best fits the data points on the scatter plot. The trend line should represent the general trend or pattern in the data.
6. Interpretation: Analyze the trend line to identify any trends, patterns, or relationships between the variables. A rising trend line indicates a positive relationship between the variables, whereas a declining trend line suggests a negative relationship. A horizontal trend line suggests no significant relationship.
It's important to note that a trend line is an approximation and may not perfectly represent the data. However, it can provide valuable insights into the overall trend and direction of the variables being studied.