Tutorial 17-Hypothesis Testing And Statistical Analysis Using Z test

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  • เผยแพร่เมื่อ 2 ต.ค. 2024
  • A Z-test is any statistical test for which the distribution of the test statistic under the null hypothesis can be approximated by a normal distribution. Z-tests test the mean of a distribution.
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ความคิดเห็น • 118

  • @mahalaxmiindapure8961
    @mahalaxmiindapure8961 8 หลายเดือนก่อน +13

    I got decision boundary between -2.33 to +2.33, z-score= -2.529, We will reject the null hypothesis means workers believe is true.

  • @MH_POLITICSS
    @MH_POLITICSS ปีที่แล้ว +4

    Decision boundry= +-2.33
    Z score = - 2.52
    Conclusion - if z score is less than -2.33 or greater than -2.33 then we reject null hypothesis. So -2.52 >-2.33 we Reject null hypothesis..

  • @madhuchandra123
    @madhuchandra123 ปีที่แล้ว +13

    Please complete the statistics playlist.

  • @robotsj2775
    @robotsj2775 ปีที่แล้ว +1

    Worst tutorial for z test
    This should not take more than 7-8 mins.
    Pls don't go into so much detail. Instead you would have solved 4-5 problems in 25 min.

  • @amartamboli6718
    @amartamboli6718 ปีที่แล้ว +40

    Null Hypothesis = 5
    Alternative Hypothesis = not equal to 5
    Significance level = 2%,1-1% either side...
    Area under curve using positive z-score table = 1-0.01=0.99=2.33(As per Z-score positive table)
    Decision Boundary = +- 2.33
    Z-score = -2.53
    Since Z-test value is less than -2.33 i/e. it is in the negative rejection region , So we reject the null Hypothesis ..

    • @salmanshaikh5851
      @salmanshaikh5851 ปีที่แล้ว +1

      Bhai mere ko to abhi bhi palle nai pada
      Kaha se tune sikha batai gake?

    • @hades840
      @hades840 10 หลายเดือนก่อน +11

      it is one tail test look there is underline on less

    • @harshshukla980
      @harshshukla980 4 หลายเดือนก่อน

      decision boundary
      2.05

    • @sarveshpandey9047
      @sarveshpandey9047 4 หลายเดือนก่อน +1

      2.33 kha se aya z table me to diya he nhi h

    • @sohamgoswami5165
      @sohamgoswami5165 2 หลายเดือนก่อน

      ​​@@hades840yes that's what i was thinking so it'll be only one tail on the left side
      so decision boundary to be found accordingly, which will be
      = 1-0.02
      = 0.98
      please check this tomorrow is my exam 🙏🏻

  • @anuraaganath
    @anuraaganath ปีที่แล้ว +10

    pmean = 5, std = 0.5, smean=4.8, n=40;
    null hypothesis = pmean = 5
    alternate hypothesis = pmean < 5
    C.I = 1-0.02 = 0.98
    z = -2.52 where the decision boundry is -2.06 as per the z table. So, we failed to accept the null hypothesis and the warranty should be revised

    • @alex-vq1yy
      @alex-vq1yy 6 หลายเดือนก่อน

      can you explain how decision boundary = -2.06
      how you calculated CI please explain

    • @owaisahmad8336
      @owaisahmad8336 3 หลายเดือนก่อน

      @@alex-vq1yy We check in the z-table and add the (column, row) beginning values for the cell where we have 0.98 => 2.0 + 0.6 = +-2.06 CI

    • @strangeboy0012
      @strangeboy0012 15 วันที่ผ่านมา

      @@alex-vq1yy C.I. = 1 -- S.I. AND DISISION BOUNDRY = -2.27 ( BY THE Z TABLE -2.3+0.03 = -2.27)

  • @DuraidKhalid
    @DuraidKhalid ปีที่แล้ว +3

    for decision boundry i use this :
    for 2% significane 1-1 on both sides 1/100=0.01 , 1-0.01=0.99
    and in z table value of 0.99 is 2.33 means +2.33 on right and -2.33 on left pls tell me am i correct ?

  • @KartikSharma12364
    @KartikSharma12364 7 หลายเดือนก่อน +1

    A chocolate company claims that their new recipe for dark chocolate bars increases the average cocoa content from the previous recipe. They conducted a study where they sampled 50 dark chocolate bars and found that the sample mean cocoa content is 85%. The population standard deviation of cocoa content is known to be 8%. Test the company's claim at a significance level of α = 0.05.
    Anyone solve

  • @importantforlifeyasharora9042
    @importantforlifeyasharora9042 3 หลายเดือนก่อน +1

    Actuall fanda ya to kisi ko pata nahi hai ya wo samjhane me inko takleef hai. Maths bhi theory ki tarah padha rahe hai😂

  • @sauravjha1714
    @sauravjha1714 ปีที่แล้ว +7

    Null Hypothesis = Mean = 5
    Alternative Hypothesis = Mean not equal to 5
    Significance level = 2%,1-1% either side...
    Area under curve using positive z-score table = 1-0.01=0.99=2.33(As per Z-score positive table)
    Decision Boundary = +- 2.33
    Z-score = -2.52
    Since Z-score falls in the negative rejection area...we reject the null Hypothesis!!!

    • @rokhaiyasultana9728
      @rokhaiyasultana9728 ปีที่แล้ว +2

      i got the sme ans!!

    • @souravsinha18
      @souravsinha18 ปีที่แล้ว +1

      No it is not a 2 tailed test so alternative hypotheis should be mean less than 5 years

    • @salmanshaikh5851
      @salmanshaikh5851 ปีที่แล้ว

      Bhai mere ko to abhi bhi palle nai pada kaha se tune sikha pata gake?

    • @sauravjha1714
      @sauravjha1714 ปีที่แล้ว

      @@souravsinha18 check your answer... My answer is perfectly right!!

    • @souravsinha18
      @souravsinha18 ปีที่แล้ว

      @@sauravjha1714 no bro I did this I am sure this is right why are u taking 1-1% on both sides when the worker says that the bulb lifetime will decrease you should take it on decreasing side and then calculate it

  • @arpitasharma28
    @arpitasharma28 10 หลายเดือนก่อน +3

    Really appreciate your efforts to upload this video... great explanation sir:)

  • @Vishal_19
    @Vishal_19 5 หลายเดือนก่อน +1

    U = 5
    sd = 0.50
    n = 40
    x bar = 4.8
    so area = 1 - 0.02 = 0.98 z_value will be 2.06 (dission boundry)
    4.8 - 5
    -----------
    0.05 * root 40 = - 2.52 we reject the null hypotheses the worker was right

    • @satishrajput1192
      @satishrajput1192 2 หลายเดือนก่อน

      I am also getting the same result.

  • @akashshakya8740
    @akashshakya8740 9 หลายเดือนก่อน +1

    pls provide lecture notes

  • @fehmeedaayoub6559
    @fehmeedaayoub6559 3 หลายเดือนก่อน

    Paired and unpaired ka concept????

  • @hardikanandani7377
    @hardikanandani7377 ปีที่แล้ว +4

    Ho = average warranty is 5 years.
    H1= average warranty is not equal to 5 years.
    Alpha = 0.02(Here it's less than 5 years ,so it's one tailed.)
    Area under curve = 1-0.02 = 0.098
    Decision boundry = +-2.06
    Z-score = -2.52
    So Ho is rejected.
    So, the worker was right I think.
    Bulb will malfunction in less than 5 years.

    • @souravsinha18
      @souravsinha18 ปีที่แล้ว +3

      yes it is correct but decision boundary should be -2.06 not + - 2.06

    • @hardikanandani7377
      @hardikanandani7377 ปีที่แล้ว

      Correct.

    • @sumiturkude1395
      @sumiturkude1395 ปีที่แล้ว

      @@hardikanandani7377 how did you find decision boundary.?

    • @shashi_kamal_chakraborty
      @shashi_kamal_chakraborty 11 หลายเดือนก่อน

      @@sumiturkude1395 It's 1 - alpha = 1 - 0.02 = 0.98. Now, z-table look up for 0.98. Which is found to be -2.06

    • @KartikSharma12364
      @KartikSharma12364 7 หลายเดือนก่อน

      A chocolate company claims that their new recipe for dark chocolate bars increases the average cocoa content from the previous recipe. They conducted a study where they sampled 50 dark chocolate bars and found that the sample mean cocoa content is 85%. The population standard deviation of cocoa content is known to be 8%. Test the company's claim at a significance level of α = 0.05.
      Solve this problem

  • @salmanshaikh5851
    @salmanshaikh5851 ปีที่แล้ว +1

    Continue Sir Continue me sahi time per aaya hu bcz mera abhi 15 ma tutorial chalra hai😂🤣

  • @ashishvinod2193
    @ashishvinod2193 10 หลายเดือนก่อน +2

    since our entire area under the curve value is = 1 -0.98 = 0.02 since it's left tail test..
    out z test value =-2.52 2.52

    • @rajsinghtomar8090
      @rajsinghtomar8090 7 หลายเดือนก่อน

      no confidence interval how i solve plz reply

    • @ashishvinod2193
      @ashishvinod2193 7 หลายเดือนก่อน

      @@rajsinghtomar8090 if confidence interval was not given then by default assume 98% confidence intervals

    • @sumitkoshti1171
      @sumitkoshti1171 6 หลายเดือนก่อน

      @@rajsinghtomar8090 bhai significance value is given 2% which is equal to 0.02, and by using significance value you can find CI from the formula significance value = 1-CI, 0.02 = 1-CI, CI = 1-0.02 = 0.98 which is 98%

  • @shailendrayadav6937
    @shailendrayadav6937 8 หลายเดือนก่อน

    Here bulb manufacturers question is a one tail test question because , worker believe that bulb will malfunction in less than 5yrs . So
    Null hypothesis= H0 = 5yrs
    alternate hypothesis = H1

  • @dhananjaykharat4812
    @dhananjaykharat4812 4 หลายเดือนก่อน

    (Z Test = -2.53)H0 has been rejected as (Z test VAlue is not in C.I range/Decision Boundry) so worker believe is correct.

  • @shaitan779gaming9
    @shaitan779gaming9 3 หลายเดือนก่อน

    Hi Krish, is it standard that we should always go with Z-test when sample size is above 30?

  • @vishujaiswal6160
    @vishujaiswal6160 ปีที่แล้ว +1

    next video pl. sir

  • @zero_analyst
    @zero_analyst ปีที่แล้ว

    Hello sir thank you for explaining
    You have mentioned in conclusion if z test is less than 1.96 or greater than 1.96 then we reject Null Hypothesis but as results came 2.31 which is greater than 1.96 so we should accept the Null Hypothesis. I am now confused can you please clarify thanks in advance

    • @itshimanshucreation8076
      @itshimanshucreation8076 11 หลายเดือนก่อน

      Bro unhone bola hai ki we accept to reject the H0 if z test is lessthen or greater then 1.96.

    • @vedchaudhari6587
      @vedchaudhari6587 9 หลายเดือนก่อน

      if it lies in range of 1.96 and -1.96 then accept it else for anything either greater or smaller , reject it.

  • @kdasurrenderedsoul7613
    @kdasurrenderedsoul7613 8 หลายเดือนก่อน

    Hare Krishna 😊
    Thank you so much for this vidoe 😊😊😊

  • @hardsoul00
    @hardsoul00 11 หลายเดือนก่อน

    Sir CHI SQUARE AND ANNOVA KA VIDEO Bna dein mera paper ha iska next month 10th november ko

  • @ovi_rav
    @ovi_rav 2 หลายเดือนก่อน

    Awesome explanation.. never gonna forget .. thank you

  • @sketchytv1321
    @sketchytv1321 ปีที่แล้ว +3

    بہت آسانی سے مشکل کنسپٹ سمجھایا ۔شکریہ

    • @EjazUddin786
      @EjazUddin786 7 หลายเดือนก่อน

      Hanji bilkul

  • @HarshitSharma-df7kx
    @HarshitSharma-df7kx 3 หลายเดือนก่อน

    sir what do we do when we do not have a 2 tail test condition ??

  • @AmitSharma-oh5uw
    @AmitSharma-oh5uw 10 หลายเดือนก่อน

    make more video correlation regression and probability in stats

  • @sandeepprasad1626
    @sandeepprasad1626 2 หลายเดือนก่อน

    All topics are well explained .Great Work

  • @muhammadansar3373
    @muhammadansar3373 ปีที่แล้ว

    According to my calculation HO is accepted

  • @sandeepprasad1626
    @sandeepprasad1626 2 หลายเดือนก่อน

    All topics are well explained .Great Work

  • @vyasishan3800
    @vyasishan3800 7 หลายเดือนก่อน +1

    Thank you Krish for putting efforts to explain this concepts.

  • @VeenaAjjodi
    @VeenaAjjodi 2 หลายเดือนก่อน

    taught better than my stats faculty

  • @rajarshiroy8794
    @rajarshiroy8794 11 หลายเดือนก่อน +1

    I have a doubt, From other definitions I think that If we have the population standard deviation we can directly move for z test since we are concerned about the sample size only when we are talking about the sample standard deviation as for n>30 sample and population SD are similar. So, I think the flowchart would be a little different. Can anybody clarify this doubt please??

  • @wewesusui9528
    @wewesusui9528 ปีที่แล้ว

    Sir anova test pr video banao baki ke saare test statistic 7 days live me hue he cover pr anova test nahi hua he

  • @xero4479
    @xero4479 5 หลายเดือนก่อน

    Sir kal paper hai aur ye pura samajh hi nahi aa raha tha, thank you🙏

  • @dishantsonawane8510
    @dishantsonawane8510 5 หลายเดือนก่อน

    Why do we consider sample size 30 for differentiating between Z test and T test. Why not some other number ? Why not 'x' percentage of the population ?

    • @raufurrahim878
      @raufurrahim878 3 หลายเดือนก่อน

      30 data points should provide enough information to make a statistically sound conclusion about a population. This is known as the Law of Large Numbers, which states that the results become more accurate as the sample size increases. The 30 is a rule of thumb, for the overall case, this number was set by good statisticians.

  • @heeralalchoudhary1587
    @heeralalchoudhary1587 ปีที่แล้ว

    Fabulous sir ..can I contact personally

  • @alphapoint389
    @alphapoint389 7 หลายเดือนก่อน

    Sir how formulas are derived?

  • @kritikasinghal2867
    @kritikasinghal2867 หลายเดือนก่อน

    Very helpful video sir

  • @Cricstory0108
    @Cricstory0108 9 หลายเดือนก่อน

    Sir konse video ha hypothesis check karne wali

  • @dilipgyawali1776
    @dilipgyawali1776 7 หลายเดือนก่อน

    if population standard deviation is given and sample size is less than 30, then Z test???please clarify.

    • @robinsunuwar6852
      @robinsunuwar6852 6 หลายเดือนก่อน

      you should go with t test if the sample size will be less than 30 we have to perform t test its basic rule.

  • @urvashirai8441
    @urvashirai8441 7 หลายเดือนก่อน

    If std not given and sample size more thn 30,thn which test is to be used?

    • @CrocksJam
      @CrocksJam 7 หลายเดือนก่อน

      if population std mean not given then we use t-test directly

  • @swapnil2881
    @swapnil2881 ปีที่แล้ว

    Sir please stat ki playlist continue rakho

  • @vishaltiwaribnt
    @vishaltiwaribnt 9 หลายเดือนก่อน

    thanks for Uploading in Hindi.....its much more understaniding.....

  • @Liku108
    @Liku108 10 หลายเดือนก่อน

    Sir what about f test

  • @theentertainmentworld3310
    @theentertainmentworld3310 ปีที่แล้ว

    Do any one get the z test value??
    I'm getting my z test value which is +0.037 and decision boundary values as +3.1 and -3.1 ,
    So i have to accept the null hypothesis
    Do anyone get any answer???
    Sir am i correct??

    • @sumitkoshti1171
      @sumitkoshti1171 6 หลายเดือนก่อน

      Nope, Decision boundary is +-2.33 and Z test value is -2.53, As -2.53

  • @Khojbysridhar
    @Khojbysridhar 3 หลายเดือนก่อน

    You are amazing

  • @235_TusharShastrakar
    @235_TusharShastrakar 7 หลายเดือนก่อน

    Is This playlist enough to learn statistics for data analytics ?

  • @ÃÑØÑŸMØÛŠ-X69
    @ÃÑØÑŸMØÛŠ-X69 ปีที่แล้ว

    please continue video on ml

  • @zarmeenakhan899
    @zarmeenakhan899 8 หลายเดือนก่อน

    can you make a video on cohort and case control as well?

  • @rishabhchauhan8612
    @rishabhchauhan8612 ปีที่แล้ว

    This topic is For Data Analytics or Data science ??

  • @rajasaad3450
    @rajasaad3450 ปีที่แล้ว

    wait for course completion !

  • @baishalibiswas7525
    @baishalibiswas7525 9 หลายเดือนก่อน

    Please complete full playlist

  • @MuhammadIbrahim-ju1tp
    @MuhammadIbrahim-ju1tp 5 หลายเดือนก่อน

    great krish respect so much value

  • @pr_ateek
    @pr_ateek ปีที่แล้ว

    Please complete the statistics playlist

  • @rohitrohit6883
    @rohitrohit6883 ปีที่แล้ว

    Sir, I am very thankful to you for this video.🙂😇

  • @MaryamAbid-p3j
    @MaryamAbid-p3j 10 หลายเดือนก่อน

    V nice Sir

  • @danielrichard7575
    @danielrichard7575 ปีที่แล้ว

    "promo sm" 🤗

  • @ashan3453
    @ashan3453 9 หลายเดือนก่อน

    the explanation is too good sir

  • @manjeshtiwari7434
    @manjeshtiwari7434 9 หลายเดือนก่อน +1

    Thank you for such an amazing lecture

    • @KartikSharma12364
      @KartikSharma12364 7 หลายเดือนก่อน

      My decision boundary is not getting correct ,can you help me

    • @manjeshtiwari7434
      @manjeshtiwari7434 7 หลายเดือนก่อน

      @@KartikSharma12364 what's issue?

    • @manjeshtiwari7434
      @manjeshtiwari7434 7 หลายเดือนก่อน +1

      @@KartikSharma12364 if accept area is 98 how can be reject 49 and 49, out of 100 98 is accept area so we have 1% reject area on both side u need to rewatch

    • @KartikSharma12364
      @KartikSharma12364 7 หลายเดือนก่อน

      @@manjeshtiwari7434 what's the correct answer of decision boundary and z test

    • @KartikSharma12364
      @KartikSharma12364 7 หลายเดือนก่อน

      ​@@manjeshtiwari7434decision boundary=2.33

  • @prashindu
    @prashindu 8 หลายเดือนก่อน

    For a two-tailed test with a 98% confidence interval, you would use 0.01 (or 1%) for the purpose of arriving at the z-score. This is because the remaining 2% is split equally between the two tails of the distribution, leaving 1% in each tail. So, you’d look up the z-score that corresponds to an area of 0.99 in a standard normal distribution table.
    However, for a one-tailed test with a 98% confidence interval, you would use 0.02 (or 2%) to find the z-score. This is because the entire 2% is located in one tail of the distribution. So, you’d look up the z-score that corresponds to an area of 0.98 in a standard normal distribution table.
    When in doubt, it’s generally safer to use a two-tailed test. This is because a two-tailed test is more conservative and does not assume a direction of the effect.

  • @vaishhh_likhii
    @vaishhh_likhii 10 หลายเดือนก่อน

    Thankyou so muchh,such a nice explaination!! best video for Hypothesis testingg......🤌