Final answer:
The margin of error for a 95% confidence interval is 1.382.
Step-by-step explanation:
To calculate the margin of error for a 95% confidence interval, we can use the formula: margin of error = critical value * standard deviation / square root of sample size. The critical value for a 95% confidence interval is 1.96 (which corresponds to a two-tailed test). Plugging in the values from the problem, we have: margin of error = 1.96 * 5 / sqrt(20) = 1.382