To find the area of a Canadian football field, you need to add 3,350 square yards to the area of the American football field.
- The area of the American football field is \( 6.4 \times 10^3 \) square yards.
- The area of the Canadian football field is:
\[ 6.4 \times 10^3 + 3,350 \]
First, let's convert 3,350 to scientific notation.
3,350 can be expressed as:
\[ 3.35 \times 10^3 \]
Now we can add the two values:
\[ 6.4 \times 10^3 + 3.35 \times 10^3 = (6.4 + 3.35) \times 10^3 \]
Calculating \(6.4 + 3.35\):
\[ 6.4 + 3.35 = 9.75 \]
Thus, the area of the Canadian football field is:
\[ 9.75 \times 10^3 \]
Now, writing this in scientific notation to two decimal places gives us:
\[ \boxed{9.75 \times 10^3} \]
So, the area of the Canadian football field is \(9.75 \times 10^3\) square yards.