The standard error (SE) can be calculated using the formula:
\[ SE = \frac{s}{\sqrt{n}} \]
where \( s \) is the standard deviation, and \( n \) is the sample size.
Given:
- Standard deviation \( s = 3.5 \)
- Sample size \( n = 5 \)
Substituting the values into the formula:
\[ SE = \frac{3.5}{\sqrt{5}} \]
Calculating \( \sqrt{5} \):
\[ \sqrt{5} \approx 2.236 \]
Now, substituting this value back into the equation:
\[ SE = \frac{3.5}{2.236} \approx 1.566 \]
Therefore, the standard error is approximately 1.566.