Data were collected on the weight, in ounces, of puppies for the first three months after birth. A line of fit was drawn through the scatter plot and had the equation w = 4.25 + 0.4d, where w is the weight of the puppy in ounces and d is the age of the puppy in days.

Question

What is the w-intercept of the line of fit and its meaning in terms of the scenario?
0.4; a puppy who is just born is predicted to weight 0.4 ounces
0.4; for each additional day after the puppy is born, its weight is predicted to increase by 0.4 ounces
4.25; for each additional day after the puppy is born, its weight is predicted to increase by 4.25 ounces
4.25; a puppy who is just born is predicted to weigh 4.25 ounces

Answer 1

The equation of the line of fit is given as \( w = 4.25 + 0.4d \). In this equation:

• \( w \) is the weight of the puppy in ounces.
• \( d \) is the age of the puppy in days.

The \( w \)-intercept of the line is the value of \( w \) when \( d = 0 \). To find the \( w \)-intercept, we can substitute \( d = 0 \) into the equation:

\[ w = 4.25 + 0.4(0) = 4.25 \]

Thus, the \( w \)-intercept is 4.25 ounces.

In terms of the scenario, this means that a puppy who is just born (0 days old) is predicted to weigh 4.25 ounces.

Therefore, the correct answer is:

4.25; a puppy who is just born is predicted to weigh 4.25 ounces.