Your 2TB drive has an unformatted space of 2 * 1000 * 1000 * 1000 * 1000 = 2,000,000,000,000 bytes. When you format it, some of the space will be used for storage management.
Noticed the subtle difference there? That's because of the extra space, 397,791,232 bytes in this case, the hard drive has. So, when you buy a hard drive labeled as 2 TB, you are getting 2 TB (2,000 GB) storage spaces.
Where hard drives are concerned, 8 terabytes is exactly 8 trillion bytes. For memory, it's actually 8.192 trillion, more or less. Between system storage space and that difference in computation, 7.2TB of actual storage sounds close to right.
What is a terabyte? When talking about data storage, we often measure whole system storage capacity in terabytes, but most individual files take up megabytes or gigabytes for large files. 1 TB equals 1,000 gigabytes (GB) or 1,000,000 megabytes (MB).
Previous studies on the genetics of human eye color used broadly-categorized trait information such as 'blue', 'green', and 'brown'. However, variation in eye color exists in a continuous grading from the lightest blue to the darkest brown.
You can code nominal variables with numbers if you want, but the order is arbitrary and any calculations, such as computing a mean, median, or standard deviation, would be meaningless. Examples of nominal variables include: genotype, blood type, zip code, gender, race, eye color, political party.