Final answer:
Counting each pair of hexadecimal numbers as one byte, the size of the provided data is 20 bytes. A checksum is a method used for error-checking in data transmission or storage, but its use cannot be determined from the given sequence of hexadecimal numbers without additional context or protocol information.
Step-by-step explanation:
The string of hexadecimal numbers provided represents a block of data, and to determine its size, we can count the number of bytes. Each pair of hexadecimal digits represents one byte. For instance, '45' or '00' are each one byte. Counting each pair as one byte in the provided sequence, we have a total of 20 bytes.
Regarding the checksum, it's a method used to verify the integrity of data. It's a value that is calculated from a string of data to detect errors that may have been introduced during its transmission or storage. From the given data alone, without a specific protocol or context, we can only speculate whether a checksum is used or not. In common practices such as network communications or file transfers, checksums are often included at the end of a data block. However, without additional information, we cannot definitively conclude if a checksum is present or what the scheme might be in this sequence of data.
Checksums are crucial in various fields where data integrity is vital, including computer science and digital communications, to ensure that the data received is the same as the data sent. Overall, the size of the data provided here is 20 bytes, but the use of a checksum cannot be determined from the sequence alone.