Express the following number in scientific notation 4,677,000

4,677,000 in scientific notation is 4.677 ×10^{6}

The number has to be less than 10 so to get that we have to move the decimal 6 places to the left: 4.677 (We don't need to worry about those 0's on the end. If the number is between 1 and 10 the exponent is positive. If the number is less than 1 the exponent is negative.
So to write 4,677,000 in scientific notation make it less than 10: 4.677 and since we moved the decimal 6 times the exponent is 6, which is more than 1 so it's positive.
Final 4.677X10^6 :)

Abbreviated as mg-25.

The answer is probably c. xylem