Joan writes four numbers on the board in standard form, and then she writes their scientific notation. The table below shows her numbers.
Row
1
Joan's Numbers
Number in standard form
7,100
-0.000041
-39.000
120.000
2.
Number in scientific notation
7.1 x 10
4.1 x 10-5
-3.9 x 104
1.2 x 106
3
4
In which row of the table did Joan make a mistake in writing the scientific notation?
1
2
3
4