To express 0.00049386 in scientific notation, you need to rewrite the number in the form of a × 10n, where a is a number greater than or equal to 1 and less than 10, and n is an integer.
First, we’ll move the decimal point in the number 0.00049386 to the right until we have a number that is between 1 and 10. In this case, moving the decimal point 4 places to the right gives us 4.9386.
Since we moved the decimal point to the right, we need to represent this change with a negative exponent. Thus, the number of places we moved (which is 4) will be negative. So, we write:
0.00049386 = 4.9386 × 10-4
This is the scientific notation for the number 0.00049386.