The answer depends on how many significant figures. To one sig fig it is 20.
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
0.000709999 rounded to 3 significant figures is 0.000710
44.981 rounded to three significant figures is 45.0
16.275 rounded to 3 significant figures is 16.3
79,966.92 rounded to three significant figures is 8.00e4
34,696 rounded to two significant figures is 35,000.
9,682 rounded to three significant figures is 9,680.
0.092347 rounded to 3 significant figures is 0.0923
0.00067 rounded to two significant figures = 0.00067
12,437 rounded to four significant figures = 12,440