DNA analysis is the process in which genetic sequences are studied. It is used by law enforcement and medical personnel to identify a particular person or species, and even specific cancers and diseases. At one point the analysis process was very limited.
To round off to the nearest tenth, means to keep one decimal digit. (To round off to the nearest hundredth would mean to keep two digits; to the nearest thousandth, three; and so on. Now, the digit in the second decimal place is 5. Therefore add 1 to the previous digit 2.
As you're rounding the to nearest tenth, this means you've got to round the 2nd digit. As the last two digits are 0.025, they round up (as anything including and over 5 rounds up), Therefore, they round to 3, meaning that the 2nd digit will not round up. Thus, 1.625 rounded to the nearest tenth is 1.6. Hope this helps :)