# Why It is one sample test?

#### Statistics 101

##### New Member
The answer key is D. just do not know why the correct answer is D. There are 2 proportions.

#### Dason

You flip a coin 10 times and get 7 heads. That also means you had 3 tails. You could lay that out in a table that said

Tails : 3

and using the same logic you used we would have 2 proportions here as well. But really the sample size is fixed so if you know one of the numbers then you know the other. There is really only one proportion that matters here.

Another way to think about it: If the problem instead said that they took a random sample of 100 students and the result was that 58 said to extend the school year into summer. Would this sound like just one-proportion now? You could figure out the # of students (and thus the proportion) that disagree with that statement but it's still just a "one-proportion" problem right?

#### Statistics 101

##### New Member
Thank you very much Dason, you made me understand completely.

#### Statistics 101

##### New Member
You flip a coin 10 times and get 7 heads. That also means you had 3 tails. You could lay that out in a table that said

Tails : 3

and using the same logic you used we would have 2 proportions here as well. But really the sample size is fixed so if you know one of the numbers then you know the other. There is really only one proportion that matters here.

Another way to think about it: If the problem instead said that they took a random sample of 100 students and the result was that 58 said to extend the school year into summer. Would this sound like just one-proportion now? You could figure out the # of students (and thus the proportion) that disagree with that statement but it's still just a "one-proportion" problem right?
Thank you very much Dason, you made me understand completely.

#### Statistics 101

##### New Member
You flip a coin 10 times and get 7 heads. That also means you had 3 tails. You could lay that out in a table that said

Tails : 3

and using the same logic you used we would have 2 proportions here as well. But really the sample size is fixed so if you know one of the numbers then you know the other. There is really only one proportion that matters here.

Another way to think about it: If the problem instead said that they took a random sample of 100 students and the result was that 58 said to extend the school year into summer. Would this sound like just one-proportion now? You could figure out the # of students (and thus the proportion) that disagree with that statement but it's still just a "one-proportion" problem right?
I have one more question if you have time to answer.
The answer key is C, I choose D, still do not understand why the answer is C. Thank you.

#### Dason

I don't think (D) is completely wrong. It depends on what the wording in that answer actually means. I think the intent was just that there might be some variability in the odometer readings. But if the inaccuracy is in such a way that it would provide a result that is biased then it's questionable whether the resulting phrase "the estimate should be fairly close to the actual distance" would be an accurate statement.

However (C) is probably the "most" wrong because the "actual" distance isn't a variable here. The actual distance is a parameter that we want to estimate and that distance isn't changing. There is a "true" distance and we are just trying to estimate it.

#### Statistics 101

##### New Member
I don't think (D) is completely wrong. It depends on what the wording in that answer actually means. I think the intent was just that there might be some variability in the odometer readings. But if the inaccuracy is in such a way that it would provide a result that is biased then it's questionable whether the resulting phrase "the estimate should be fairly close to the actual distance" would be an accurate statement.

However (C) is probably the "most" wrong because the "actual" distance isn't a variable here. The actual distance is a parameter that we want to estimate and that distance isn't changing. There is a "true" distance and we are just trying to estimate it.
thanks again. The actual distance is the parameter that can not be variable. It is a fixed number.

#### Statistics 101

##### New Member
the answer key is A, I have no idea why A is correct. I choose C.