Terrific! Re: the comments below about why do all the extra math, seems that it helped elaborate the explanation to make it all crystal clear!! Great video! I've lost count of the number of videos I've watched about z-scores & tables, and you're the first person to say right up front that the 4 digit numbers in the table are percentages of the curve represented by the z-value. Bravo!!
I have a midterm tomorrow with this stuff on it and I was completely lost because of the language barrier between my professor and the class. Thank you so much for making sense of this for those of us who are not math-minded!
The subject is broken down to small steps; and step by step explanation makes the subject become clear, and illustrative, and thus very easy to follow to understand. Just one word: Awesome !! Thank you for making, not only this subject but also this world, one more step easier to understand.
***** I think the book make the problem look harder than it is, there are unnecessary words in the textbook or the test,they do this to confuse the student, you have to read the problem more than twice
Great Job! I'm so glad you went through each step and chose not to cut corners because College Professors want to see how you arrived at your answer not just what it is.
very layman, i came here after another TH-cam tutorial which explanation was too complicated. you the man, i finally understood, especially when you brought out the Z table
I lost the count how much hours I spend watching videos to understand the Z-Score but it is so simple actualy. If in all high schools would be explained things as it was explained in this video, we has a so much succestfull graduated specialists around us. I one more time get confirmation, all is possiible to lear, just all depends how user friendly explanation used. Thanks!
Omg! I’m taking statistics online and I feel like I don’t have a teacher. Thank goodness I found such a great and concise explanation of the concepts are! Thank you for sharing your math brain with us!
Because the Z score of 60 (-1.5) in this case is below the average (the average is 75, and the average always has a z score of zero). If you're looking for something BELOW the Z score of 60, that's the entire area shaded from 60 and to the left (-1.5 and below ad infinitum), but if you're looking the probability of every score ABOVE 60, you subtract the probability of 60 and below (probability of -1.5 standard deviations from the mean is .0668) from 1 to find the remaining probability, which is .9332, or 93.32 percent. Hopefully I explained it clearly enough, but if I didn't please let me know.
Thank you very much! very easy to understand and you do an excellent job explaining it. This probably just saved me an hour reading through the Z scores section in the chapter.
Why in another video of your you say that z scaore is the Xbar - population mean divided by population or sample standard deviation divided by the square root of sample size?
+Syazlina Aasim Percentage means per 100 and gives a reference i.e 93.22% probability means 93.22 of 100 chance. You could still use 0.9332, but I prefer using percentage since it gives you a reference and hence is more precise.
I am just wondering...If you know that the area under a normal bell curve = 100 and you have calculated the area of section one, why can't you just subtract section 1 from 100? It gives you the same answer as what you got with less work.
Why here you say that to find the Z score the formula is Z = X-M(Aver. Pop.)/Sigma and in another video, the video Z-test vs T-test, you say that the formula for Z test is Z = x (Avr Sample) - M (Aver. Pop.) / Sigma / Square Root of n (the Sample Size)? What is the difference between Z score and Z test and why are their formulas different?
+Farah Syazwani The standard deviation is basically the average distance from the mean. Simply square of all your variables minus the mean , add them up, and then take the square root of that sum.
Can you help me with this problem please? Online Books A Consumer Reports Research Center survey of 427 women showed that 29.0%of them purchase books online. a. Among the 427 women who were surveyed, what is the number of women who said that they purchase books online? b. Find a 95% confidence interval estimate of the percentage of all women who purchase books online. c. Can we safely conclude that less than 50% of all women purchase books online? Why or why not? d. Can we safely conclude that at least 25% of all women purchase books online? Why or why not? e. What do the results tell us about the percentage of men Thank you
You don't need to know what section 2 is. If you know under -1.5 is 6.68% and that's 60 points, then your probability is everything above -1.5 or the "other side" which is the remainder - 93.32% which together is 100% It's a good exercise but burns time on the test.
Great explanation but why make things more complicated my dividing into section 2 and 3 while you could just mark the whole area of +60 and do 100 - 6,68? Anyways, thanks for the help :)
haha there is actually shorter way to do this,,, so,, we got our 1.5 ,,in the z-score table,, it is 0.0668,, after u get that u can just subtract it 1,, so 1-0.0668 would = to 93.32 %
It works in this case, but I guess (I'm not sure, you can correct me please) you do this for confidence interval when you're given already with a probability that it's usually 95% or 99%, 1-alpha=99%
I've been struggling with z-scores ALL DAY in less than 15 minutes you've made it all so clear! So glad I found this! Thank you!
Terrific! Re: the comments below about why do all the extra math, seems that it helped elaborate the explanation to make it all crystal clear!! Great video! I've lost count of the number of videos I've watched about z-scores & tables, and you're the first person to say right up front that the 4 digit numbers in the table are percentages of the curve represented by the z-value. Bravo!!
I have a midterm tomorrow with this stuff on it and I was completely lost because of the language barrier between my professor and the class. Thank you so much for making sense of this for those of us who are not math-minded!
The subject is broken down to small steps; and step by step explanation makes the subject become clear, and illustrative, and thus very easy to follow to understand.
Just one word: Awesome !! Thank you for making, not only this subject but also this world, one more step easier to understand.
intro to stats midterm in two hours. You just saved my bacon!! Thank you so much for your videos!
We pay at School and have to learn here,
Classes are taught expecting students to study multiple hours a week
***** Then they shouldn't cost so much!
this is grade 11 math so you shouldn't be paying to be taught it.
***** I think the book make the problem look harder than it is, there are unnecessary words in the textbook or the test,they do this to confuse the student, you have to read the problem more than twice
it really depends on the country you're in.
Great Job! I'm so glad you went through each step and chose not to cut corners because College Professors want to see how you arrived at your answer not just what it is.
very layman, i came here after another TH-cam tutorial which explanation was too complicated. you the man, i finally understood, especially when you brought out the Z table
I lost the count how much hours I spend watching videos to understand the Z-Score but it is so simple actualy. If in all high schools would be explained things as it was explained in this video, we has a so much succestfull graduated specialists around us. I one more time get confirmation, all is possiible to lear, just all depends how user friendly explanation used. Thanks!
Omg! I’m taking statistics online and I feel like I don’t have a teacher. Thank goodness I found such a great and concise explanation of the concepts are! Thank you for sharing your math brain with us!
. . . Good video and thanks. But why mess around with area 2 and 3 when you could have simply subtracted 6.68% from 1 in the first place?
.
I agree. No wonder people hate stats. He should be using a z-table showing tail probabilities. It would make it a lot easier to do it your way.
I think he just wants to point out the mean is at center
can you explain the rationale behind subtracting one please
why subtract from one
Because the Z score of 60 (-1.5) in this case is below the average (the average is 75, and the average always has a z score of zero). If you're looking for something BELOW the Z score of 60, that's the entire area shaded from 60 and to the left (-1.5 and below ad infinitum), but if you're looking the probability of every score ABOVE 60, you subtract the probability of 60 and below (probability of -1.5 standard deviations from the mean is .0668) from 1 to find the remaining probability, which is .9332, or 93.32 percent. Hopefully I explained it clearly enough, but if I didn't please let me know.
Thank you SO much. I was having problems with z-scores for my midterm tomorrow, and this lays it out perfectly.
Love, love your style of teaching. I was able to understand ALL your steps. Thank you so much 😘😘
Thank you so much for making this video! I have been really struggling with my Statistics class and now I understand perfectly. You are saving my GPA!
+Courtney Elizabeth (Kotoni) Same :')
Thanks, I thought him.
You. Are. A. Hero.
An easier way is to subtract 0.06681 from 1, since the area under a normal distribution bell curve is equal to 1. Hence, 1-0.06681 = 0.9332 or 93.32%
I was wondering why he complicated it so much, thank you!
You have done and excellent job explaining this concept!! I just added this video as a resource for my grad students.
Thank you very much! very easy to understand and you do an excellent job explaining it. This probably just saved me an hour reading through the Z scores section in the chapter.
i finally understand Z scores and Normal Distribution!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Thanks, I thought him.
Why calculate area under (2) and (3), when we can find the answer by subtracting area under (1) from 100% ??
exactly I had the same thought in my mind..
it was a mistake. If he was solving for the probability below 75 and above 60, then his method is correct.
Bye@@AllaahuAkbarr
I missed this lesson due to illness...you are my savior damn
You rock!!! Thank you! You make it so clear and simple.
You just saved me from failing my midterm, you are an angel.
Thanks so much. My stats professor can hardly speak English so this is a life saver.
Thanks for your efforts, this is so helpful to me. Greetz from Holland!
Awesome !! Just watched it only once and i understood it right away. Thanks a ton !
thanks this helped me a lot
it is simpler than any video I have found so far
I have been searching for a simple explanation for three weeks
It’s very smart to announce your next video so that we can follow you as you develop these concepts…
Good shit bro. I be passing my exams since 11 grade cuz you bro. You gotta become my tutor cuhhh I'll pay you 💰
awesome techniques of teaching, smoothly understood...thnx
Better explained than the majority of instructors...
when checking the z table what is to be checked at then top row? why did you take 0.00 and not 0.01?
Still watching this in 2017. Thank you for the help!
Korfor kjeme det opp ein spilleliste om statistikk når eg søker på vitenskaplig metode?
Why in another video of your you say that z scaore is the Xbar - population mean divided by population or sample standard deviation divided by the square root of sample size?
great video! thanks! where is the link for t score or t test?
is it still considered to be correct if i write the probability as 0.9332 and not in percentage?
+Syazlina Aasim Percentage means per 100 and gives a reference i.e 93.22% probability means 93.22 of 100 chance. You could still use 0.9332, but I prefer using percentage since it gives you a reference and hence is more precise.
do one on sampling distribution!!
best video I've seen on the topic! Thank you so much!
I am just wondering...If you know that the area under a normal bell curve = 100 and you have calculated the area of section one, why can't you just subtract section 1 from 100? It gives you the same answer as what you got with less work.
thank you sooo very much...finally a simple way to understand....thank u
Great teaching with a concrete explanation ,,thak you so much
You are amazing. Thanks for helping me study.
That made sense. Thank you for putting your knowledge out here for others to use!!
Thanks for clearing my confusion about z-score. This tutorial helps me a lot. :)
This is a cool presentation. You are a GREAT teacher
Thank you !
Can you include in this video how to find z scores with the Calculator eg TI- 84 please.
Nice explanation to rely on for assignments about the z scores values
So clear to understand, thank you so much
It is very clear and easy understand, but it has so many steps
This was a very clear explanation. Thanks alot!
Good video.We could use the table shaded to the left then find the complement of it for ease.
Why here you say that to find the Z score the formula is Z = X-M(Aver. Pop.)/Sigma and in another video, the video Z-test vs T-test, you say that the formula for Z test is Z = x (Avr Sample) - M (Aver. Pop.) / Sigma / Square Root of n (the Sample Size)? What is the difference between Z score and Z test and why are their formulas different?
why do you use a different z score formula for hypothesis testing tho? :/
Excellent example! Thank you
Could have just subtracted 0.0668 from 100 and shaved off 5 minutes.
+John Kirchner 6.68*
I thought the d=same
Oh my god I have a final in a couple hours and I just understood what Z scores are thank you so so much
hello, why did you use the .00 and not the .01. I don't understand the significance of it
How do we get the areas how do we compute them are they fixed? I'm at 8:43. Sorry for the question I'm not really good at stats.
The Area is 100%, he got 6.68 as the area below that.. so logically 100 - 6.68 is the 93.32
Eid thanks for answering. I realized that there is a z table.
Demetria Samantha z
Thanks - very clear explaination!
Thanks for the explanation...so comprehensive
So grateful for this video. Thank you!
thanks bro, helped a lot... wish u were my teacher
Wow!!! U are amazing! Thanks for breaking this down!
Nice video clear and simple presentation , I don't why you got less views may be your title is not appealing to the first viewrs
LoL! just find the z score and subtract that number from 1 and multiply by 100! (z score is .0668) so, 1-.0668=.9332 x 100= 93.32%
Thankyou. THANKYOU
you did what my textbook couldn't!!
+C Watkins Seriously! I'm sitting here reading my text book like wtf! This was so helpful!
Thanks, I thought him.
Thanks, I thought him.
Great job, very clear.
Mnay Thanks for this great video ! Superb !
I have one question.What if the standard deviation is not given? and how to find it.Please help me asap !!!!
+Farah Syazwani The standard deviation is basically the average distance from the mean. Simply square of all your variables minus the mean , add them up, and then take the square root of that sum.
Thanks for the explanation!
Thanks a lot ..helped me a lot to begin with ..
What's the underlying logic behind calculating the values in the Z table?
better than my textbook. Thanks!
Dude..why are you going around in circles. Jus do total, which is 100%, minus 6.68%. You get 93.32%. End of story.
You jus confused all the beginners.
I just came to the comment section to leave this exact comment.
Actually, by doing it the way he did I have a much better understanding of the concepts after struggling for two days.
Thanks for the great explanation.
this channel is awesome
Thank you so much mate, you are a god among men! haha thanks again for this upload.
A very good video thanks much appreciated
This video is very helpful. Thank you! : )
thanks!!! Finally I understand what the table means.
Thanks for these videos!
Great video! Thank you very much! I finally understand! :D
Tremendous help, thank you!
Can we all fund for a better mic for him?! thanks for the good explanation buddy! :)
thank you!!! helped me for my finals hehe
you are doing well bro. please keep up the good work. ;).
Can you help me with this problem please?
Online Books A Consumer Reports Research Center survey of 427 women showed that 29.0%of them purchase books online.
a. Among the 427 women who were surveyed, what is the number of women who said that they purchase books online?
b. Find a 95% confidence interval estimate of the percentage of all women who purchase books online.
c. Can we safely conclude that less than 50% of all women purchase books online? Why or why not?
d. Can we safely conclude that at least 25% of all women purchase books online? Why or why not?
e. What do the results tell us about the percentage of men
Thank you
Beta Marashi no
You don't need to know what section 2 is.
If you know under -1.5 is 6.68% and that's 60 points, then your probability is everything above -1.5 or the "other side" which is the remainder - 93.32% which together is 100%
It's a good exercise but burns time on the test.
wow you're awesome ! thank you so your amazing incredible teaching !
Thanks, I thought him.
TV in
Thanku so much :) it was very helpful
Thank you so much. Very helpful!!!
Thanks so much! A great help.
Thank you! Very helpful😃
Great explanation but why make things more complicated my dividing into section 2 and 3 while you could just mark the whole area of +60 and do 100 - 6,68? Anyways, thanks for the help :)
Thnaks for the Great Explanation
haha there is actually shorter way to do this,,, so,, we got our 1.5 ,,in the z-score table,, it is 0.0668,, after u get that u can just subtract it 1,, so 1-0.0668 would = to 93.32 %
It works in this case, but I guess (I'm not sure, you can correct me please) you do this for confidence interval when you're given already with a probability that it's usually 95% or 99%, 1-alpha=99%
Very nicely explained
Why not saying directly that :
.the left probability is 0.0668 then the probability of above 60 (ie the rest of curve) is
1-0.0668 = 0.9332
Dude, you good fam!... Salute!