how do i repair a cut cable?

we have cable tv in our new house, but the previous owners didn’t have cable in the upstairs bedroom. There is an existing cable there, but when I go to the basement where the source is, that cable has been cut. I found the end that was cut from it. Is there any way to hook this up myself? I called the cable company but they want to charge me WAAAY too much to come and do it. Can I do it myself or will I have to pay them?
Thanks