Item: if a piece of lab equipment is not working properly you should

stop the experiment and tell your science teacher.
try to fix it with the of your lab partner.
try to keep on working to finish the lab.
move to another lab table.

you didn't give any options but heres what i can tell you: an inference is likely to change based on additional observations. the latter is something that you have seen or sensed using your sensory organs while the former is like a conclusion out from what you have observed.