346.7500 has five significant figures

Answer 1

No, it actually has seven significant figures.

Basic rule:

(1)When number has decimal point---count from left to right counting all numbers after the first non-zero number

ex.-->.009367 has 4 sig figs

ex.-->9.367 has 4 sig figs

ex.-->9.367000 has 7 sig figs

(2)When number doesn't have a decimal point---count right to left counting all numbers after the first non-zero number

ex.-->12 has 2 sig figs

ex.-->120 has 2 sig figs

ex.-->1207800 has 5 sig figs

Answer 2

Yes, that is correct. A number with five significant figures means that there are five digits in the number that are all considered to be significant in determining the precision of the value.