Z- test
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- Опубликовано: 11 сен 2024
- How to calculate Z value and the corresponding value? Also will understand how to interpret the result.
Note: Unlike in this example, the number of samples (for more accurate results by z-test) should be atleast 30.
Couldn't understand Chi and Z the in class, watched many videos but there's no clear explanation and here you explained everything in a very simple way in just few minutes. Thank you so much sir 🙏🙌❤️
When sample size greater than or equal to 30 then we conduct Z test👍
Absolutely... otherwise the result isn't accurate... This is just for the sake of understanding...
@@VectorsAcademy yes u r right and thanks for clearing the concept but still take sample size 30 or more caz this exapmle will confuse students bt t and z test ...otherwise u should tell in ur video that it is only for understanding purpose
No, t test is held when sample size is less than or equal to 30 but but but with unknown population parameters. Here S.D is given.
Here sample is 25 lesser than 30 why we conducted z test ?
because we had population parameters, not sample ones! @@respecteverytalent0k
All doubts cleared after watching this single video. Sir please make one on t Test
Thankyou sooo much. You have no idea how helpful it was. It's indeed the best video on z test. Simple, quick and to the point.
You explained it soo well that it cleared many things sir 🙏🏻
Great sir.... very nice way to express. ......this comment is behalf of all the lecturers what you hav uploaded....
This is the best one for z-test to my knowledge
My whole doubts cleared in
Today in 30 minutes i understood chi and z test .. thank you sir 😍
The best explanation available on youtube, thank you sir!
Awesome. Understood very easily simply short and sweet. Keep going.
Thankyou sir☺️..ur presentation is very simple , clear and crisp. I haven't found a person who explains this well. ❤
Sir, we have take level of significance 0.05 in the illustration, then why you are considering the p value at 0.09 (10%). Please clarify.
Same question
it is because of the value -1.39, notice the z written in the corner of the table, they take -1.3 and 0.09, basically divided the value of z = -1.39 into -1.3 and 0.09 and then they got the value of 0.0823.....please correct me if i am wrong
Sir u are brilliant in the way u simplify stats . Thank u
Thank you for explaining the concepts in very understanding and easy method. Kindly provide more videos on statistics especially for parametric and non parametric tools.
Great video but N
If we have standard deviation then might be..... Its good question from you
sir wwhat about t test
Alpha=5% rejection level will be at both side i.e, 2.5% isn't it?
u are correct but when u write 5% without percentage sign ,it becomes 0.05
Nope, that's a one-tailed test, all we want to know is if their weight is significantly lower than the average. You're thinking about a two-tailed test, where the value tested can't be neither higher or lower
That would be only if the hypothesis is non-directional
Nice explanation sir
Cannot explain how thankful i am. Thank you!!!
Realy got the concept clearly..... Thankyou to the team
95% CI to be considered, and both the side we need to consider 2.5%. Request you to correct the same or please clarify why u have taken 90% CI
You are right.. It should be 2.5 on both sides...
In fact if you read the research question.. It should be one tailed test.. 5% on one side...
The graph should just be used understand the meaning of significance level...
Sorry for trouble
Brilliantly explained and presented. Thank you
Best video for z-test on youtube
Thankyou sir. This is the best explainantion. It cleared all of my doubts.
Nice explanation, it took me some time to understand how you got 0.0823 from the table
Thanks a lot , really explained in a simple and clear manner
Very clear explanation.all the best carry on same work.many users need such videos.with your example I understood concept very
Well. Need some explanation about assumption about z test.but it's ok.
How do you do it differently if it's a 1-tailed vs 2-tailed test?
Greater than-one tailed(right)
Less than-one tailed(left)
Equal-two-tailed
Very clear explanation. Thankyou sir.
Excellent video. Lucid application. Appreciate it.
Here . The sample size is less than 30 kadha..so.. how can we take this as a large sample test and z test
Great Explanation.
Good Example taken for the case. Thanks.!
In normal distribution the bell never touches the lines
Why we check the value in 0.09 how to know where to check?
I think rejection level on both sides sud have. 025 value n mid point of the curve sud have. 95.
Please correct me if m wrong. Thank you
Yes.. And actually in this example.. It should be a one tailed test...
Thankyou for explaining in a clear manner
nice video but you said "accept the null hypothesis". shouldn't it be "cannot reject the null hypothesis" ?
1 video for t test please sir
To perform z test sample size should be greater than or equal to 30
Yes.. both the queries are correct...
Firstly this should be a one tailed test by looking at our aim...
Secondly more the sample size, more accurate will be the results... (for research purposes its important, for study purposes it's fine)
This was a nice video sir. I liked the practicality of your example and the steps involved. I did not understand how did we decide it will be 1 tailed test and not 2 tailed. Also if it would have been a 2 tailed test, what difference would it cause in our rejection region? Would love to hear your response. Thanks.
If we need to find people above poverty... It's one tailed...
But in the same graph if we need to find middle class, we need to remove lower class as well as higher class... (It's 2 tailed)
Excellent information sir thanks
Clear cut explanation...thank you so much!!
why we used Z-Test intead of One Sample T-Test since our sample size is less than 30 observations?
Bro end statement is accepted as the null hypothesis but in analysis fact observed Z- value is >Z-expected value in table. So the Null hypothesis rejected this problem.
Awesome brilliantly explained
3:32 what is 0.9 in that graph?
Today probability is 1...
Out of which 0.05 on left and 0.05 on right is rejection zone.. 1-0.05-0.05 = 0.9..(90%)
0.9 is acceptance zone...
@@VectorsAcademy Thank you so much sir!.. You have made statistics easy for me!
@@gaaraofddarkness happy to help...
Sir the z test is applied for large samples right! Here in this example you have taken a sample of 25 boys.
You are right... This is just for illustration of how to apply ztest
Sample size is less than 30 in this case, should we consider z test based on sample size?
Sir can you teach through SPSS. because your teaching method is excellent and easily understandable
Wait can i ask what to do if the zed value has three digits after the decimal point? I am lost🧍
That shouldn't be a problem...
If you still find a problem dealing with it.. just consider 2 digits after decimal.. ignore other values..
@@VectorsAcademy THANK YOU SO MUCH💓💓💓💓
Sir here sample size is 25 so how we can apply z test ???
Z test is applied where sample size is more than 30
Nicely spotted... You are the first one to do it... 😊 And thank you.
You are absolutely right... I just took a random example to show how the Ztest is applied.. Didn't took the note of no. of samples...
Practically it shouldn't be applied for smaller sample as it MIGHT lead to incorrect results...
@@VectorsAcademy if the sample size is 30 or more,we can use z test.also,if the sample size is less than 30 and Standard deviation is known,then also we can use z test.
excellent explanation sir 🙌🙌
Sir can we apply z test in case of non probability sampling
Since the sample size is less than 30,will the z test work?
Z test will give highly reliable results only if sample size is greater than 30...
For study purpose we can use it for less than 30 but not for research.
Sir t test video I m unable to find..
super explanation sir can u pls also make the video on ROC and AUC
Surely will try to make one
explanation is very nice SIR
Here we were supposed to perform a one-tailed z test right??
Yes.. well spotted...thank you...
We never accept the Null Hypothesise. Either reject it OR Fail to reject it. :)
Superb explanation.
Thank you for the quality information.
Wouldn't H1 be µ > 32, not µ < 32
Short and sweet 🙌 thanks
Sir t test ko bhi explain krein or Yeh btaein ky kaise Pata chaly ga knsa test use krna hy
But sample is of only 25 students.....we should use T Test....can we use z test too even in this case????
Yes..
more the sample size, more accurate will be the results... (30 in case of z-test)
(for research purposes its important, for study purposes it's fine to have a little small size.. not too small though..)
Good video. Though Correction: n here is number of elements in the sample i.e. sample size not number of samples.
Very nicely explained.
As always Amzing video Sir. Thank you so much for this act of kindness. Keep It Up!
Your comments...😍
Amazing explanation
Very well explained...Thank you
thank you sir clear explanation
What is the difference between z test and student's t-test?
Excellent explanation
su miralya majama ??
very well taught sir! thank you so much
I guess sir, you should have taken a different example and also probably where H1 could have been accepted
Hey Body , your calculation for Z test is wrong ! because the sample size is less than 30 you have to look for p value in T Dist. table . also your alternative hypotheis was not stated problely.
Jazak Allah Khair 🌸
I want to learn T test
Where is this?
Thank you so much sir ❤️
one tailed test...you have to take 0.025 to compare with P value...for two tailed you can compare with 0.05
Could u explain assumption of parameter test what condition must need to conduct parameter test?
Why didn't we split the alpha? in both the tails?
For this particular question.. it should be single tail
But sir if the sample size is n > 30 only then we should use Z test but here the sample is 25 which is less than 30 ....so ???
You are right.. for any research with n>30 we should use Z test. This video was just made to show the application of Z test. Sorry for it though..
Is S.D. a fixed value ?....where to find it.....sorry ...just started to understand statistics
It's a calculated value for the population data... it simply means, the average deviation of values from mean...
In this particular sum, its already given to us...
We are soon launching the full 'basics of statistics' course... If interested let us know...
@@VectorsAcademy has it uploaded now?
2:24 square or underoot?
Well explained sir
I think this video has mixed up an one-sided z test with a two-sided z-test and hence is confusing, I request the instructor in the video to make this part clear.
Yes.. It should be one sided z-test..
why did u choose the value by 0.9 in that table?
Tolerance is 0.05.. i.e. 5 % on both sides.. = 10% so 90% acceptance level. (0.9)
Very well teached
Please explain the properties and applications of z and t test ?
Sir t test video?
thanks sir... this helped a lot
goat🙏
amazing lecture
Excellent 🎉
Excellent
How to check Z Table, not cleared
X>30 z-test or not?