Final answer:
When multiplying 0.0078406m by 9.45020m, the product should have 5 significant figures because the number with the least amount of significant figures used in the calculation has 5 significant figures.
Step-by-step explanation:
In the product 0.0078406m×9.45020m, you must look at the number of significant figures in each number separately before multiplying. The first number, 0.0078406m, has 5 significant figures (the leading zeros are not significant). The second number, 9.45020m, contains 6 significant figures. When multiplying, the number of significant figures in the result should be the same as the number with the least amount of significant figures used in the multiplication. So, since 0.0078406m has 5 significant figures, the product should be rounded to 5 significant figures as well.