Z- test

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.

[@malathi.27]

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 🙏🙌❤️

[@dolly4347]

All doubts cleared after watching this single video. Sir please make one on t Test

[@soumyasaxena5151]

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.

[@ajitraut3829]

When sample size greater than or equal to 30 then we conduct Z test👍

[@VectorsAcademy]

Absolutely... otherwise the result isn't accurate... This is just for the sake of understanding...

[@mshahzad6164]

​@@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

[@hazrat_nawaz]

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.

[@respecteverytalent0k]

Here sample is 25 lesser than 30 why we conducted z test ?

[@TragicGFuel]

because we had population parameters, not sample ones! @@respecteverytalent0k

[@ravindrasemwal5243]

Great sir.... very nice way to express. ......this comment is behalf of all the lecturers what you hav uploaded....

[@saikongz]

This is the best one for z-test to my knowledge

[@1life865]

Today in 30 minutes i understood chi and z test .. thank you sir 😍

[@albinakash1483]

Thankyou sir☺️..ur presentation is very simple , clear and crisp. I haven't found a person who explains this well. ❤

[@ialimustafa]

The best explanation available on youtube, thank you sir!

[@RajputMpsingh]

You explained it soo well that it cleared many things sir 🙏🏻

[@SairamDasireddy]

My whole doubts cleared in

[@kannayaa9626]

Awesome. Understood very easily simply short and sweet. Keep going.

[@rohanshinkre]

Sir u are brilliant in the way u simplify stats . Thank u

[@sanika6916]

Thankyou sir. This is the best explainantion. It cleared all of my doubts.

[@maheshkumars2593]

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.

[@mtechtransportationenginee2931]

Nice explanation, it took me some time to understand how you got 0.0823 from the table

[@rashidmalshamsi]

Brilliantly explained and presented. Thank you

[@premikaramvittal8807]

Realy got the concept clearly..... Thankyou to the team

[@harishkumar5002]

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.

[@meetalipalekar3168]

Same question

[@priyankakalita8102]

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

[@aparnamadhumohan]

Very clear explanation. Thankyou sir.

[@nilagangbaka4184]

Cannot explain how thankful i am. Thank you!!!

[@meow__lalizabeth]

Great video but N

[@ravindrasemwal5243]

If we have standard deviation then might be..... Its good question from you

[@madhupal7071]

Alpha=5% rejection level will be at both side i.e, 2.5% isn't it?

[@Tamannashomoeopathy]

u are correct but when u write 5% without percentage sign ,it becomes 0.05

[@robertstryker2]

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

[@lsw3364]

That would be only if the hypothesis is non-directional

[@naziya9967]

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.

[@kunalrai4524]

Thanks a lot , really explained in a simple and clear manner

[@vibhabandhu6175]

Thankyou for explaining in a clear manner

[@mehboobmg28]

Best video for z-test on youtube

[@__AmanSingh-wt1ic]

Nice explanation sir

[@rahulpathak9649]

Excellent information sir thanks

[@akshaysingh7962]

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.

[@VectorsAcademy]

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)

[@idealmathsdeosir9308]

explanation is very nice SIR

[@governmentteacherpreparati347]

Sir can you teach through SPSS. because your teaching method is excellent and easily understandable

[@sangeethasaga]

Clear cut explanation...thank you so much!!

[@zulikhakhan4540]

Awesome brilliantly explained

[@bikramadityaghosh1450]

Excellent video. Lucid application. Appreciate it.

[@anuragmukherjee1878]

Great Explanation. Good Example taken for the case. Thanks.!

[@Vivek-xm2wx]

thank you sir clear explanation

[@terryterry3733]

super explanation sir can u pls also make the video on ROC and AUC

[@VectorsAcademy]

Surely will try to make one

[@jpaiims]

Superb explanation.

[@sharonchetia54]

Good video. Though Correction: n here is number of elements in the sample i.e. sample size not number of samples.

[@madhupal7071]

To perform z test sample size should be greater than or equal to 30

[@VectorsAcademy]

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)

[@rafiarehan4632]

Jazak Allah Khair 🌸

[@__AmanSingh-wt1ic]

1 video for t test please sir

[@gurungnirmal]

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

[@VectorsAcademy]

Yes.. And actually in this example.. It should be a one tailed test...

[@vaibhavbhuskute9522]

Very well explained...Thank you

[@navnithrajsn1705]

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

[@VectorsAcademy]

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

[@ankathilokesh4410]

excellent explanation sir 🙌🙌

[@saurabhmishra3394]

Amazing explanation

[@veeramania9381]

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.

[@ishaqhussain3892]

Very nicely explained.

[@anjushacdas]

Well explained sir

[@funnyclub2764]

As always Amzing video Sir. Thank you so much for this act of kindness. Keep It Up!

[@VectorsAcademy]

Your comments...😍

[@theomitchell416]

How do you do it differently if it's a 1-tailed vs 2-tailed test?

[@Blink_dara]

Greater than-one tailed(right) Less than-one tailed(left) Equal-two-tailed

[@samikshasharma5892]

very well taught sir! thank you so much

[@brijesh0808]

We never accept the Null Hypothesise. Either reject it OR Fail to reject it. :)

[@praweshthapa4328]

Why we check the value in 0.09 how to know where to check?

[@sanaqureshi6533]

Excellent explanation

[@abuda7em20]

why we used Z-Test intead of One Sample T-Test since our sample size is less than 30 observations?

[@emreselek5836]

nice video but you said "accept the null hypothesis". shouldn't it be "cannot reject the null hypothesis" ?

[@karanmalpani4149]

sir wwhat about t test

[@Ujjayanroy]

one tailed test...you have to take 0.025 to compare with P value...for two tailed you can compare with 0.05

[@prachigoel4541]

Please explain the properties and applications of z and t test ?

[@kunikakhobragade6953]

Very well teached

[@ayeshaejaz7740]

Sir t test ko bhi explain krein or Yeh btaein ky kaise Pata chaly ga knsa test use krna hy

[@aminuzzaman4214]

Sir can we apply z test in case of non probability sampling

[@pasankeragala2866]

Short and sweet 🙌 thanks

[@aartipalande6588]

Here we were supposed to perform a one-tailed z test right??

[@VectorsAcademy]

Yes.. well spotted...thank you...

[@funshow4697]

Excellent 🎉

[@kavindersingh2469]

Thank you for the quality information.

[@aquarius-zabir983]

Thank you so much sir ❤️

[@jillashravya6574]

Here . The sample size is less than 30 kadha..so.. how can we take this as a large sample test and z test

[@PrabhjotKaur-vl5rb]

In normal distribution the bell never touches the lines

[@manishmotwaniwyadgplzle2379]

Pls upload the mathematical derivation too!

[@pureplantation]

amazing lecture

[@DgfRhgy-nz7fk]

Excellent

[@kondurusrikanth7620]

nice explaination

[@DeepakAdhikari-mv8wy]

Sample size is less than 30 in this case, should we consider z test based on sample size?

[@parimalagrace399]

Sir the z test is applied for large samples right! Here in this example you have taken a sample of 25 boys.

[@VectorsAcademy]

You are right... This is just for illustration of how to apply ztest

[@KathirNatarajan-wk3nc]

Could u explain assumption of parameter test what condition must need to conduct parameter test?

[@ameliacarter2692]

thanks sir... this helped a lot

[@gaaraofddarkness]

3:32 what is 0.9 in that graph?

[@VectorsAcademy]

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...

[@gaaraofddarkness]

@@VectorsAcademy Thank you so much sir!.. You have made statistics easy for me!

[@VectorsAcademy]

@@gaaraofddarkness happy to help...

[@priyankakalita8102]

please put a video on t test

[@muskanmalik8570]

Sir here sample size is 25 so how we can apply z test ??? Z test is applied where sample size is more than 30

[@VectorsAcademy]

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...

[@jumaniqbal8206]

@@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.

[@ruchipatel1948]

Sir t test video I m unable to find..

[@nilagangbaka4184]

Wait can i ask what to do if the zed value has three digits after the decimal point? I am lost🧍

[@VectorsAcademy]

That shouldn't be a problem... If you still find a problem dealing with it.. just consider 2 digits after decimal.. ignore other values..

[@nilagangbaka4184]

@@VectorsAcademy THANK YOU SO MUCH💓💓💓💓

[@theomitchell416]

Thank you.

[@ruchidesai7448]

Sir t test video?

[@kdasurrenderedsoul7613]

Hare Krishna 😊

[@abhishekchakrabarty2930]

Since the sample size is less than 30,will the z test work?

[@VectorsAcademy]

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.

[@ranaadnan8626]

Excellent 👍

[@peashooter-s5d]

goat🙏

[@muhammadbilalmughal1469]

AOA sir kndly make it clear that from where did u get this table?

[@VectorsAcademy]

That's a pre defined table available in all reference books.. you can google it as well.

[@treasuretitus1205]

What is the difference between z test and student's t-test?

[@izakventer9454]

Thank you kind sir

[@RMS2701]

great sir

[@sarojmoud7209]

Is S.D. a fixed value ?....where to find it.....sorry ...just started to understand statistics

[@VectorsAcademy]

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...

[@meenalverma5379]

@@VectorsAcademy has it uploaded now?

[@kushjadav1831]

su miralya majama ??

[@aizakhalid9810]

I want to learn T test Where is this?

[@brins6]

Pls do a video on Normal and Poisson distribution

[@VectorsAcademy]

Ok.. Will try at the earliest

[@ajaymaila3177]

Sir how can we take p value with respective z value from the table?

[@VectorsAcademy]

Google the table.. or it given in all reference books