To determine the sign of the product \(-16.8 \times \frac{3}{7}\), we need to analyze the signs of the numbers involved.
- \(-16.8\) is negative.
- \(\frac{3}{7}\) is positive because both the numerator and the denominator are positive.
When the product of a negative number and a positive number is calculated, the result is negative.
Therefore, the sign of the product \(-16.8 \times \frac{3}{7}\) is negative.