To find the area of a Canadian football field, we start with the area of an American football field, which is given as:
\[ 6.4 \times 10^3 \text{ square yards} \]
Next, we know that a Canadian football field is 3,350 square yards larger than an American football field. Therefore, we need to add 3,350 square yards to the area of the American football field:
\[ \text{Area of Canadian football field} = 6.4 \times 10^3 + 3350 \]
Next, we need to express 3,350 in scientific notation to combine it better with the area of the American football field. To convert 3,350 to scientific notation:
\[ 3350 = 3.35 \times 10^3 \]
Now we can add the two areas together. Note that both numbers are in terms of \(10^3\):
\[ \text{Area of Canadian football field} = (6.4 \times 10^3 + 3.35 \times 10^3) \]
Combining the coefficients (since they have the same power of ten):
\[ = (6.4 + 3.35) \times 10^3 \]
Calculating the sum of the coefficients:
\[ 6.4 + 3.35 = 9.75 \]
Thus, we have:
\[ \text{Area of Canadian football field} = 9.75 \times 10^3 \]
Finally, in scientific notation rounded to two decimal places, the area of the Canadian football field is:
\[ \boxed{9.75 \times 10^3} \]