78.24 since you had two decimal places in the multiplier you'll have two in the answer.
The final answer.is only as accurate as the least accurate component in the calculation, so use the significant figures of the measurement with the fewest.
Two - the trailing zeros are just placeholders.
That depends on the context in which it is found, or the calculation(s) involved. It should have no more significant figures than the value with the least number of sig. figs.
It's 10, correct to two significant figures.
If the zeros are significant figures then 900 is correct to 3 significant figures. If rounding off has occurred then the answer could be 1 sf or 2sf. For example : If the original number was 903 and rounding off to the nearest ten was required then 900 is correct to 2 significant figures. If the number was 927 and rounding off to the nearest hundred was required then 900 is correct to 1 significant figure.
63.6615
192
It might have been possible to answer the question if the "following" multiplication had followed. But since you did not bother to make sure that it did, I cannot provide a more useful answer.
There should be 3.
6 of them.
The answer depends on what operations were used. There should normally not be more significant figures in the answer than in any of the numbers used in the calculation.
The least number of significant figures in any number of the problem determines the number of significant figures in the answer.
7.34
4 significant figures.
which is the correct product of the significant figures 3.278 and 4.23.
4,566 to 3 significant figures is 4,570.
10 significant figures.