To find the initial value (y-intercept) of a linear relationship defined by the ordered pairs (3, 42.25) and (5, 50.75), follow these steps:
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Determine the slope (m) using the formula:
\( m = \frac{y_2 - y_1}{x_2 - x_1} \)
For the points (3, 42.25) and (5, 50.75):
\( m = \frac{50.75 - 42.25}{5 - 3} = \frac{8.5}{2} = 4.25 \) -
Use the slope-intercept form of a line:
\( y = mx + b \)
Plug in one of the points to solve for b (the y-intercept). Using (3, 42.25):
\( 42.25 = 4.25(3) + b \)
Simplifying gives:
\( 42.25 = 12.75 + b \)
\( b = 42.25 - 12.75 = 29.5 \)
The initial value (y-intercept) is 29.5.