Why 82K Ohm?

So if I assume the Resistance of my Load that uses the 48V with 1000Ohm and I want to reduce the voltage to 4V. Could i just put a 77Ohm Resistance in series to the load? I calculated it with U_reduced/U_total = R_divider/R_total with U_reduced= 4V U_total = 48V R_total = 1000Ohm + R_divider R_divid...

Hello, Please correct me if this is the wrong Forum for my problem. I would like to ask how you would realize a simple DC Voltage measurement on a 48V DC line on a Rpi3. I am currently finishing my masters in renewable energies at university in germany ( I am german so please excuse if my english is...