To determine the score for a baby that is 18 inches long with respect to the reference point of 20 inches, we can calculate the difference between the baby's length and the reference length.
The reference length: 20 inches
The baby's length: 18 inches
The difference:
20 inches - 18 inches = 2 inches
Since the baby is shorter than 20 inches, the score will be negative.
To determine the score using the given examples:
- A score of +1 corresponds to being 1 inch over the reference point.
- A score of -4 corresponds to being 4 inches under the reference point.
Given the consistent scoring pattern, we can see that each inch below the reference point results in a score that appears to be proportional.
From the information provided:
- For each inch below 20 inches, we can derive a score.
Let's observe the first provided example to derive a scoring system:
For scores:
- 21 inches = +1 (20 inches = 0; +1 deviation from 0)
- 16 inches = -4 (20 inches = 0; -4 deviation from 0)
Now evaluate the scores per inch:
- From 20 inches to 21 inches (1 inch above) = +1
- From 20 inches to 16 inches (4 inches below) = -4
We can discern the following:
- Each inch below results seems to take away 1 point, so it is reasonable to say that a deviation of 2 inches results in a score of -2.
Thus for 18 inches, the calculation would be:
- 20 inches - 18 inches = 2 inches, therefore the score would be -2.
So, a baby that is 18 inches long receives a score of -2.
Final answer: -2