Questions: Use technology to find an equation of the line of best fit for the data. Round your answers to the hundredths place.
Equation: y=-.8x+5
Identify the correlation coefficient.
Transcript text: Use technology to find an equation of the line of best fit for the data. Round your answers to the hundredths place.
Equation: $y=-.8 x+5$
Identify the correlation coefficient.
Solution
Solution Steps
Step 1: Identify two points on the line of best fit
The provided equation of the line of best fit is \(y = -0.8x + 5\). We can use this equation to identify two points on the line.
Let \(x = 0\), then \(y = -0.8(0) + 5 = 5\). So, one point is \((0, 5)\).
Let \(x = 5\), then \(y = -0.8(5) + 5 = 1\). So, another point is \((5, 1)\).
Step 2: Calculate the differences in x and y
Using the two points \((0, 5)\) and \((5, 1)\), we can calculate the difference in x-values and y-values.
Difference in x: \(5 - 0 = 5\)
Difference in y: \(1 - 5 = -4\)
Step 3: Estimate the correlation coefficient
The line of best fit has a negative slope, indicating a negative correlation. The points are relatively close to the line, suggesting a strong correlation. Since the correlation coefficient ranges from -1 to 1, where -1 represents a perfect negative correlation and 1 represents a perfect positive correlation, we can estimate the correlation coefficient to be close to -1.
The given equation \(y = -0.8x + 5\) suggests a strong negative correlation. By observing the graph, the points cluster fairly close to the line of best fit, but not perfectly. Therefore, the correlation coefficient should be a negative value close to -1. A reasonable estimate, based on the scatter plot and the equation, would be around -0.9.