ase answer the question below for all parts. Please show all work and write clearly. Thanks

A sender needs to send out 5 numbers (3, 11, 12, 9, 7). Answer the following:

1. Find the checksum at the sender site
2. Find the checksum at the receiver site if there is no error
3. Find the checksum at the receiver site if the first data is changed to 5.
4. Find the checksum at the receiver site if the first data is changed to 5 and the second data is changed t