The volume \( V \) of a right rectangular pyramid can be calculated using the formula:
\[ V = \frac{1}{3} \times \text{Base Area} \times \text{Height} \]
First, we need to calculate the base area. The base of the pyramid is a rectangle, and its area \( A \) can be calculated as follows:
\[ A = \text{Length} \times \text{Width} = 6.75 , \text{inches} \times 10.25 , \text{inches} \]
Calculating the base area:
\[ A = 6.75 \times 10.25 = 69.1875 , \text{square inches} \]
Next, we can use the height of the pyramid, which is given as 22.3 inches, to find the volume:
\[ V = \frac{1}{3} \times 69.1875 , \text{square inches} \times 22.3 , \text{inches} \]
Calculating the volume:
\[ V = \frac{1}{3} \times 69.1875 \times 22.3 \]
First, calculate the product:
\[ 69.1875 \times 22.3 = 1545.1875 \]
Now, divide by 3:
\[ V = \frac{1545.1875}{3} = 515.0625 , \text{cubic inches} \]
Thus, the volume of the pyramid is:
\[ \boxed{515.0625} , \text{cubic inches} \]