Thanks Daniel, This is much better for my way of learning. Reading the book and listening in class really works for some people. However, your videos breaks it down to where I can hit replay until I totally get the lesson.
Hey, Thanks for the simple explanation. I was wondering though if the sampling distribution of sample means is a normal distribution..and we have to calculate 95% Confidence interval.. Can we not use the property of Normal dist that 95% data lies between -2sigma and +2sigma ? Why do we choose a z score of 1.96 instead ?
Hey Ananya!!! Great question, and you've obviously got a strong working knowledge of the normal distribution and the central limit theorem!!! You're right +/- 2 sigma captures ~ (approximately) 95% of the distribution. 1.96 is very close to 2.00, and is the z-score that capture (more accurately) 95% of the distribution. It's sort of splitting hairs, and if you just need a quick approximation, using 2.0 (instead of 1.96) will get you close enough.
I am a fan of your videos. Please keep up the good work. However, for this particular lesson, I have a question. Normally we need to work with sample instead of the whole population and in this video you also mentioned that the mean of the the population is unknown. My question is: in order to calculate the confidence interval of the population mean, one of the parameter that we need to know is the standard deviation (sigma) of the POPULATION. Then how do we know (or calculate) this standard deviation value?
Hey Alfred!!! Okay so if you know the alpha risk, you can use a normal probability table to translate that into the Z-score. I cover this in this video: th-cam.com/video/6hH7LwCw8qY/w-d-xo.html And if you want a copy of those normal probability tables, just shoot me an email at Andy@CQEAcademy.com and I can share that with you! -Andy
Thanks Daniel,
This is much better for my way of learning. Reading the book and listening in class really works for some people. However, your videos breaks it down to where I can hit replay until I totally get the lesson.
Andy, I just wanted to thank you. I passed the PE exam today. Your videos really helped, esp for the quality section of the PE exam.
You’re absolutely welcome, I’m more than happy to help!!!!
Great video!
Thank you so much! I have been struggling with this concept for about a week now, and you just laid all of my confusion to rest. Thanks
Hey Daniel!!! Glad I could be of service!
Keep that good work going! Helped me so much, thank you!
Thanks for this video, I am doing your course snd this is a great complement
Thanks Angel, glad you like it!
Great work, keep on posting videos. Thank you
You're welcome!
I'm Glad you like it!
-Andy
Thank you for this informative video!
You are so welcome!
-Andy
Thank you Mr. Andy for this amazing vedio.
You're welcome Mahgoub!!!!!
Thanks for the video.
You're welcome!!!
Hey, Thanks for the simple explanation. I was wondering though if the sampling distribution of sample means is a normal distribution..and we have to calculate 95% Confidence interval.. Can we not use the property of Normal dist that 95% data lies between -2sigma and +2sigma ? Why do we choose a z score of 1.96 instead ?
Hey Ananya!!! Great question, and you've obviously got a strong working knowledge of the normal distribution and the central limit theorem!!!
You're right +/- 2 sigma captures ~ (approximately) 95% of the distribution. 1.96 is very close to 2.00, and is the z-score that capture (more accurately) 95% of the distribution.
It's sort of splitting hairs, and if you just need a quick approximation, using 2.0 (instead of 1.96) will get you close enough.
@@CQEAcademy I was giving myself a hard time to connect all the dots. Thank you so much for clarifying 🙌😊
@@ananyaagarwal7108 You're absolutely welcome!!! Glad to help
I am a fan of your videos. Please keep up the good work. However, for this particular lesson, I have a question. Normally we need to work with sample instead of the whole population and in this video you also mentioned that the mean of the the population is unknown. My question is: in order to calculate the confidence interval of the population mean, one of the parameter that we need to know is the standard deviation (sigma) of the POPULATION. Then how do we know (or calculate) this standard deviation value?
amazing vid thx g
Thanks!!!
Appreciate It
You're welcome!
Where is Z located? Alpha is known
Hey Alfred!!!
Okay so if you know the alpha risk, you can use a normal probability table to translate that into the Z-score.
I cover this in this video:
th-cam.com/video/6hH7LwCw8qY/w-d-xo.html
And if you want a copy of those normal probability tables, just shoot me an email at Andy@CQEAcademy.com and I can share that with you!
-Andy