Literally 85% of the interviews I conducted ended on the note well, "He is Black, so, what does he know about what we need." Other comments as well, that I cannot even post here lol...
Yeah, I'm afraid they're racist. However, you may want to start over on you study.
Your sample size is too small to come to any reliable conclusion. However, it's still an experiment, so there are still some precautions you need to take.
I can already tell you how you conclusion is faulty, and it has nothing to do with the sample size.
Nope, it makes plenty of sense. Although 5 of the 15 I interviewed were not family members at all. And from my notes 7 of the 15 actually used the N word, as we were in a private setting and felt they could really have at it out they feel about it.
10 of the people you interviewed were your own family members. Although not always the case, family members do to tend to share similar views and hold fairly similar values. I'm also going to go out on a limb and guess that the other 5 people you talked to were friends of the people you interviewed. Chances are pretty good that your family members live within a circle of people who have strong negative opinions towards blacks.
If you want your study to hold more weight, first, you need to talk to Republicans who live in different parts of the state/county/city. Make sure the title of your experiment reflects the source of your interviewees. If everyone you talked to live within the same city/town as you, then make sure your experiment is titled to reflect that it's the opinions of various people from the city/town. If you talked to different people throughout the country, then have the title of the experiment reflect this instead.
Second, since you're probably not in position to do blind interviews with random people, you need to at least make sure the people you interview have little-to-no relation between one another.
With what you have now, you might just be proving how racist your own family is.
I have no idea how lenient your teacher is. I've seen teachers pass some pretty pathetic projects before, and it might be easiest to stick with what you have if you teacher is the lenient type. However, if your teacher does pass you, know that your study is incredibly flawed.