Summary
Summary OCR A-Level Biology 6.2.9 Chi-Squared Test
Revision summary of key knowledge from OCR A-Level Biology 6.2.9 Chi-Squared Test.
[Show more]
Connected book
Book Title:
Author(s):
- Edition:
- ISBN:
- Edition:
Seller
Follow
Content preview
Chi-Squared Test( O−E)²
Formula: χ² = ∑
E
E = Expected Number
O = Observed Number
Degrees of Freedom = Number of Classes – 1 (N-1)
Significance Level = 5% = 0.05
Null Hypothesis = There is no significant difference between the observed and expected
date at the 5% significance level, any difference is due to chance
If χ² > CV, difference is significant, reject null hypothesis
If χ² < CV, difference is due to chance, accept null hypothesis
Example
Category Observed (O) Expected (E) (O-E)² (O−E)²
E
Yellow, Round 169 162 49 0.30
Green, Round 54 54 0 0.00
Yellow, Bumpy 51 54 9 0.17
Green, Bumpy 14 18 16 0.88
χ² 1.35
Degrees of Freedom = 4 - 1 = 3
CV = 7.82
1.35 < 7.82
χ² < CV
Accept null hypothesis, difference is due to chance
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller izzylewington04. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £2.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
52355 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now