These videos are great! I'm taking a statistics and probability course for extra credit right now but I don't have the time to go to class so I'm studying on the weekends. This will help me get a 5 out of 5 on the exam (swedish grading system) . Thank you!
Can you double check the calculations of the class satisfaction variance for x=5, with P(x) =.351. For (x-u)2P(x) = I got .351 x 1.69 =.593 not .488. ???
Thanks Brandon for all that you do. I did the calculation myself and found these Mean - 3.93, Var - 1.24, StDev - 1.11. However, my question here was how can I get this done in Minitab. Need help with this one. Any response from any one would be appreciated. Thank you
Some constructive criticism: at 20:46 for example, in the 5th column, last two rows, you write out (sigma)^2 and (sigma). It confused me quite a bit first because I thought you meant that (sigma)^2 = (x - u)^2 , which isn't consistent with the formula stated at the very bottom. A quick explanation in the video would be helpful :) .
Brandon, thanks for the amazing video. But I've never saw the variance equation to contain this *P(x) at the end before. I always saw it as the sum of (x - mu)^2 divided by the number of observations. Is this not the same thing? In the die roll example we would get to 2,92 at the end too if we just had divided by six.
Why would it be combination but not permutation to calculate the different groups of successes since where the failures are in the trial matters? So the order of the failure and success matter, but why isn't it permutation?
Hello Mohsin! For discrete random variables the variance and standard deviation are different than for continuous. It is based on the expected value and probability of each discrete outcome; very much like "weighting" each discrete outcome. What I am pretty sure you are thinking about are continuous random variables as opposed to discrete. Hope that helps! - B
+Brandon Foltz I was seeing the video on the same topic on a channel named jb statistics in which he says 'expected value' is not the same as mean. The expected value we calculate thru 'adulteration' [ i.e we first calculate probability and then multiply with outcomes etc ] while the simple mean we calculate simply without the values of the problem being adulterated. So, I feel the proper word wud be apparent mean. What are ur thoughts on it. here is the link for that video.
@@BrandonFoltz I think - this is not because of descrete or not, but because of probability - in probability we devide every time by total number of events, i.e. in probability embeded devision by N.
🎯 Key Takeaways for quick navigation: 01:00 *🎲 Introduction and overview of the video content* - Video aimed at individuals new to Stats or finite mathematics - Concepts in the video applicable to both statistics and finite mathematics - Focus on extending the discussion on discrete random variables to variance and standard deviation 02:27 *🔍 Understanding the variability in random variables through variance and standard deviation* - Variance and standard deviation measure the spread of data from the mean - Importance of variance in making statistical assumptions about data - Use of variance in comparing data sets and drawing conclusions 04:07 *📊 Equation and calculation of variance explained* - Breakdown of variance calculation formula - Importance of understanding each step in the variance calculation process - Application of the variance formula to discrete random variables 08:22 *🎲 Example with a die roll and calculation of mean, variance, and standard deviation* - Mean of a die roll explained - Calculation process for variance in a die roll scenario - Relationship between variance, standard deviation, and the mean in the context of a die roll 11:36 *📈 Example with class satisfaction surveys and calculation of variance and standard deviation* - Calculation of variance in the context of class satisfaction surveys - Interpretation of variance and standard deviation in relation to expected value - Visual representation of probability distribution skewed towards higher satisfaction levels Made with HARPA AI
