To determine the score for a baby that is 18 inches, we first need to establish a relationship between the score and the length in inches.
From the information provided:
- A 21-inch baby has a score of +1.
- A 16-inch baby has a score of -4.
We can calculate the change in score per inch. The difference in inches between the two babies is:
21 inches - 16 inches = 5 inches
The difference in scores is:
+1 - (-4) = 1 + 4 = 5
Now, we can calculate the score increase per inch:
Score change per inch = (Score change) / (Inch change) = 5 / 5 = 1
This means that for every inch, the score increases by 1.
Next, we need to calculate the score for an 18-inch baby. The difference in inches from 16 to 18 is:
18 inches - 16 inches = 2 inches
Now we can find the score for the 18-inch baby by adding the score change (based on our per-inch calculation) to the score of the 16-inch baby:
Score for 18 inches = Score for 16 inches + (Score change per inch * Inch change) Score for 18 inches = -4 + (1 * 2) Score for 18 inches = -4 + 2 Score for 18 inches = -2
So, the score for an 18-inch baby would be -2.