Stats Independent Variables

<p>Okay so I'm taking AP Stats right now and I'm doing really good, but the only thing I can't grasp is determining if two variables are inde-****<strong><em>-pendent of each other. My teachers decent, but he can only explain things one way and if you don't get it, you don't get it. I understand that to calculate if they are independent you have to do some bull$</em></strong> with a 2-way table and all. But I just don't understand how that determines they are independent. I mean, if they are equal, wouldn't that make them not independent?? I'm mad confused bro.</p>

<p>Variables are independent if the second outcome has no bearing on the first. </p>

<p>Example-</p>

<p>The sex of your children is independent because it doesn’t matter what your first child was (boy or girl) the second child will still have an equal chance of beig a boy or girl (probability is .5 for both— not necessary of all independent variables, the probabilities don’t have to equal, just a coincidence)</p>

<p>Okay, so they’re independent if they have the same probability? I’m not sure how you can apply that to something like comparing job type and sex. There’s no ‘second outcome.’</p>

<p>No not same probability </p>

<p>Being independent means that the two variables don’t affect each other. </p>

<p>Another example-</p>

<p>Drawing a red King from a deck of cards or drawing a black card. Whether you select a black card or not doesn’t affect the probability of getting a red king (with replacement)</p>

<p>Alright yea that makes more sense, thanks.</p>

<p>No prob .</p>

<p>lol how can you be in AP stats and not know that that is the first thing you learn. Secondly another thing to remember is that mutually exclusive events are not independent. Such events are those where if one happens the other outcome cannot</p>

<p>rude ^^</p>

<p>i still don’t quite understand everything.</p>