Final answer:
The y-intercept of the linear equation is 7.5 pounds.
Step-by-step explanation:
The y-intercept of a linear equation
A linear equation is typically represented in the form y = mx + b, where m is the slope of the line and b is the y-intercept. In this case, the equation represents the relationship between time in weeks (x) and weight in pounds (y). Since the baby weighed 7.5 pounds when she was born, the y-intercept is 7.5.
To find the y-intercept, we set x to 0 in the equation. So, when x = 0, y = mx + b simplifies to y = 0 * m + b, which becomes y = b. Therefore, the y-intercept is the value of y when x = 0.