It is not possible to answer the question without information about the number of significant figures required.
12,437 rounded to four significant figures = 12,440
5 of them.
It is 6.7 when rounded to 2 significant figures
You didn't say how many significant figures. But, rounded to six significant figures it would be 5206.00
0.00721004 rounded into three significant figures is 0.00721
9,976,200 rounded to two significant figures is 10,000,000.
16.275 rounded to 3 significant figures is 16.3
0.000709999 rounded to 3 significant figures is 0.000710
44.981 rounded to three significant figures is 45.0
0.00721004 rounded to three significant figures is 0.00721
79,966.92 rounded to three significant figures is 8.00e4
1,399.54 rounded to three significant figures is 1.40e3