Answer:
(see below)
Step-by-step explanation:
The sentence given is:
Jin didn't return my text about hanging out this weekend thus I can only assume that he's really busy.
First, notice how there's a little unevenness between "weekend" and "thus". That's because there is no conjunction or anything to bridge them together. That means that they are two separate sentences.
A period will separate the sentences. A semicolon separates two similar sentences. This means that the bridged sentences must both be about a general topic. Such as:
My dog's name is Daisy; she is the most lovable dog!
Because these two sentences are similar, you can choose whether to use a semicolon or period.
After doing that, keep in mind that after every transition—first, furthermore, however, to conclude, additionally, etc.—there must be a comma. This is extremely important.
Thus is a transition, which means it requires a comma after it.
So now your sentence should look like this:
Jin didn't return my text about hanging out this weekend; thus, I can only assume that he's really busy.
or
Jin didn't return my text about hanging out this weekend. Thus, I can only assume that he's really busy.
There is nothing else to correct, so your final product should be one of the above.