anonymous
  • anonymous
What does A with a line over it mean in statistics?
Mathematics
  • Stacey Warren - Expert brainly.com
Hey! We 've verified this expert answer for you, click below to unlock the details :)
SOLVED
At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident, similique sunt in culpa qui officia deserunt mollitia animi, id est laborum et dolorum fuga. Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum soluta nobis est eligendi optio cumque nihil impedit quo minus id quod maxime placeat facere possimus, omnis voluptas assumenda est, omnis dolor repellendus. Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat.
katieb
  • katieb
I got my questions answered at brainly.com in under 10 minutes. Go to brainly.com now for free help!
theEric
  • theEric
It might depend on the context, but the line over a variable usually means its the average of the variables values. I'll post an example in a second. It's common in statistics!
theEric
  • theEric
\(x_1 = 3\\x_2 = 5\\x_3=1\\x_4=3\) Then... \(\bar x=\dfrac{3+5+1+3}{4}=\dfrac{12}{4}=3\)
theEric
  • theEric
\(x\) might be things like the number of cookies eaten in one day, or something like that. Then all the subscripts, the \(_1\), \(_2\), \(_3\), and \(_4\), indicate the day number.

Looking for something else?

Not the answer you are looking for? Search for more explanations.

More answers

anonymous
  • anonymous
|dw:1378569430980:dw| My professor put it on his practice quiz and didn't explain it. It is not even in the book.
theEric
  • theEric
So, \(\sf P(\bar A\ and\ B)\) Is this a logic class? Or math proofs? I think sometimes the line over might indicate "not", like, an element not include in set \(A\). So, what class is this? I might be able to help better if I know!
anonymous
  • anonymous
It is an intro stats class
theEric
  • theEric
Okay, then the line over A probably means the average of \(A\). What is the whole question, so I can see if it makes sense!
anonymous
  • anonymous
He also put on the quiz the Union and Intersect symbols which are also NOT in the book. And he barely talked about the symbols. He assumed we knew.
theEric
  • theEric
And I don't like it when professors assign new things for homework, haha! It's like they're the teacher, but you'll have to go somewhere else to learn since it's out of school. Hopefully he doesn't mind if the answers aren't all good. :)
theEric
  • theEric
That is ridiculous. Again, then, he could be using it as the "not."
theEric
  • theEric
So, read it like "not A and B." So, I guess you know some set stuff, if you were exposed to unions and intersections?
anonymous
  • anonymous
Right, he wrote on the board, P (A union B) and asked us what it meant. Noone said anything and he was surprised. I told him it wasn't in the book and he said you can't get everything from the textbook. Then why the * are you asking us for it and why did you assign this book?
theEric
  • theEric
I guess \(A\) and \(B\) are sets. Then "\(A\) and \(B\)" means you want to talk about the elements that are in both \(A\) and \(B\), which is where the sets "intersect." That looks like \(A\cap B\) in one notation. Sets are used in statistics, too. It's just like \(X\) is the set containing \(x_1\), \(x_2\) and so on. And there might be another set for how many cookies ANOTHER person eats each day, like \(Y\). After you put in all the numbers for the \(x_1\) stuff and \(y_1\) stuff, the intersection will be easier to see. If there is a number in both, then it is in the intersection \(X\cap Y\).
anonymous
  • anonymous
The problem is a table Gender Bonds Stocks Balanced male .18 .20 .25 female .12 .1 .15 There are two parts to the question Find P(A with bar over it and B) Find P(A with bar over and B with bar over it) Sorry I don't know how to make that symbol.
theEric
  • theEric
Ah! \(P\) is probably the "power set." Does that sound familiar?
anonymous
  • anonymous
power set?
theEric
  • theEric
I guess not! It is often written as \(P(something)\). And I think P might be written fancily. Power set is a set of... sets... Do you know what a subset is?
anonymous
  • anonymous
No I don't. It is a intro to Business stats class if that means anything. It is a requirement.
theEric
  • theEric
I see. Well, it's important for all statistics, especially for working on probability. A "proper subset" is a set that contains no more than some of the elements of another set. Take away the "proper" and it is just a subset, where all of its elements are within another set. The symbol for subset is \(\subset\) or \(\supset\). For proper subsets, you will see \(\subseteq\) or \(\supseteq\). If \(A\) is a subset of \(B\), then you say \(A\subset B\). If \(A\) is a proper subset of \(B\), you say \(A\subseteq B\). That's what I learned, I think. So, \(A=[1,\ 2, 3]\), we'll say. And so there are subsets of \(A\), like \([1]\) \([2]\) \([3]\) \([1,2]\) \([1,3]\) \([2,3]\) and \([1,2,3]\). The powerset is the set of \(A\) is all of those subsets! \(P(A)=[\ [1]\) \([2]\) \([3]\) \([1,2]\) \([1,3]\) \([2,3]\) \([1,2,3]\) \(]\) I have to go, take care!
goformit100
  • goformit100
"Welcome to OpenStudy. I can guide regarding this useful site; ask your doubts from me, for it you can message me. Please use the chat for off topic questions. And remember to give the helper a medal, by clicking on "Best Answer". We follow a code of conduct, ( http://openstudy.com/code-of-conduct ). Please take a moment to read it."
theEric
  • theEric
I guess I should have used commas: \(P(A)=\large\left[\normalsize [1],\ [2],\ [3],\ [1,2],\ [1,3],\ [2,3],\ [1,2,3] \right]\)

Looking for something else?

Not the answer you are looking for? Search for more explanations.