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For more information, please see full course syllabus of AP Statistics
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Lecture Comments (8)

1 answer

Last reply by: Sandahl Nelson
Sat Mar 25, 2017 10:03 PM

Post by So-Hee Park on March 25 at 08:49:43 AM

Hi Prof.Nelson,

I was really confused when you wrote the null hypothesis for the examples. I was thinking that the null hypothesis should be worded same as the problem. For example, "Example III:" question is worded "Does favorite subject differ by gender?" and you wrote the null hypothesis is "Favorite subject does NOT differ by gender."

However, in the interpretation when the null hypothesis is rejected, you said we have evidence to support the null hypothesis - favorite subject does differ by gender."

I don't understand how the null hypothesis in the hypothesis and the null hypothesis in the interpretation differs.
It seems like I am misunderstanding something! Please help!

1 answer

Last reply by: Firebird wang
Wed Oct 12, 2016 10:56 PM

Post by Xiaming Jin on May 7, 2016

Hi Professor Nelson,

Finally finished all lectures in AP statistics!
I just want to say thank you very much!!

These courses are the only thing I use for all my studying in statistics. And your explanation and examples in every lecture are very clear and help me a lot! Also thank you for your patient answers about my questions!

Hope to do well in AP exam several days after haha

Thanks again!

Xiaming Jin

1 answer

Last reply by: Sandahl Nelson
Mon Apr 4, 2016 3:19 PM

Post by Bhavya Vaghasia on April 3, 2016

 Hello, I think for the conditions, it should be that all the expected values be greater than 5.

1 answer

Last reply by: Sandahl Nelson
Mon Apr 4, 2016 3:12 PM

Post by Liuzixuan Hu on March 29, 2016

For example II: Chi-Squared Goodness of Fit. your expected value should be 76.25 not 75.25.

Hypothesis Tests for Categorical Data (Chi-Squared Tests)

Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.

  • Intro 0:00
  • Lesson Overview 0:11
  • How Do We Know to Use a Chi-Squared Test? 0:27
    • Categorical Data
  • Chi-Squared Goodness of Fit Test 1:50
    • One Categorical Variable with Counts in Each Category
    • What We Have Seen
    • New Question Type
  • Example I: Chi-Squared Goodness of Fit Test 4:02
    • Chi-Squared Goodness of Fit Steps Overview
    • Step 1: Hypothesis
    • Step 2: Expected
    • Step 3: Conditions
    • Step 4: Calculate
    • Step 5: P-Value & Chi-Square Distribution Table
  • Example II: Chi-Squared Goodness of Fit Test 22:04
    • Step 1: Hypothesis
    • Step 2: Expected
    • Step 3: Calculate
    • Step 4: P-Value & Chi-Square Distribution Table
  • Chi-Squared Test of: Homogeneity or Independence/Association 34:31
    • Homogeneity
    • Independence/Association
  • Example III: Chi-Squared Test of: Homogeneity or Independence/Association 37:55
    • Step 1: Hypothesis
    • Step 2: Expected
    • Step 3: Conditions
    • Step 4: Calculate
    • Step 5: P-Value & Chi-Square Distribution Table
  • As a Test of Association 52:53
    • As a Test of Association
  • Example IV: Chi-Squared Test of: Homogeneity or Independence/Association 55:05
    • Step 1: Hypothesis, Expected, and Conditions
    • Step 2: Calculate
    • Step3: P-Value & Chi-Square Distribution Table
  • Example V: Chi-Squared Test of: Homogeneity or Independence/Association 1:02:48
    • Step 1: Hypothesis
    • Step 2: Expected and Conditions
    • Step 3: Calculate
    • Step 4: P-Value & Chi-Square Distribution Table