To find the slope and y-intercept of the linear relationship between the variables \(x\) and \(y\), we can use the points provided.
- Calculating the slope (m):
The formula for the slope between two points \((x_1, y_1)\) and \((x_2, y_2)\) is:
\[ m = \frac{y_2 - y_1}{x_2 - x_1} \]
Let's use the points \( (5, 16.5) \) and \( (7, 21.5) \) to calculate the slope:
\[ m = \frac{21.5 - 16.5}{7 - 5} = \frac{5}{2} = 2.5 \]
Now, let's confirm this by using a different pair of points, \( (7, 21.5) \) and \( (11, 31.5) \):
\[ m = \frac{31.5 - 21.5}{11 - 7} = \frac{10}{4} = 2.5 \]
Thus, the slope is consistent and equals \(2.5\).
- Finding the y-intercept (b):
To find the y-intercept, we can use the slope-intercept form of the equation of a line, which is given by:
\[ y = mx + b \]
We can use one of the points, say \( (5, 16.5) \), for this:
\[ 16.5 = 2.5(5) + b \]
Calculating:
\[ 16.5 = 12.5 + b \] \[ b = 16.5 - 12.5 = 4 \]
So, the y-intercept is \( 4 \).
Now, summarizing the results:
- Slope: \( 2.5 \)
- Y-intercept: \( (0, 4) \)
Therefore, the correct answer is:
slope 2.5, y - intercept (0 , 4).