The margin of error (ME) for a confidence interval is calculated as half the width of the interval. The confidence interval given is $[14.70, 19.20]$.

To find the margin of error, use the formula:

$\text{Margin of Error} = \frac{\text{Upper Bound} - \text{Lower Bound}}{2}$

Substitute the given values:

$\text{Margin of Error} = \frac{19.20 - 14.70}{2} = \frac{4.50}{2} = 2.25$

So, the margin of error is 2.25.

Thus, the correct answer is B) 2.25.

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Related questions:

1. How do you calculate a confidence interval for a sample mean?
2. What is the relationship between the margin of error and the sample size?
3. How does the confidence level affect the margin of error?
4. Can you calculate the margin of error for a confidence interval when only the sample mean and standard deviation are given?
5. What is the effect of increasing the sample size on the margin of error?

Tip:

When calculating the margin of error, always check the interval bounds carefully to ensure the subtraction is accurate.