Sampling Distribution and Hypothesis testing
Hypothesis testing
1. Starting point: Null hypothesis: tails = 50%
2. Alternative hypothesis: Tails ≠ 50%
3. Probability 6 times tails: 1/64 = 1.6%
4. Conclusion: 1.6% < 5%
Reject null hypothesis & accept alternative hypothesis
Central question of the course: How is it possible to use one sample to draw a conclusion
about the population?
- Make a confirmation based on a sample about a population
Example; Chips
Previous research: µ regular = 80 grams
Research question: Is the mean consumption of light chips (in grams) higher than the mean
consumption of regular chips (in grams)?
Hypotheses
Null hypothesis: People eating light chips eat on average as much as people
eating regular chips → H0: µlight = 80
Alternative hypothesis: People eating light chips eat on average more than people eating
regular chips → H1: µlight > 80
Previous research: µregular = 80
50 people: light chips
Sample results: 𝑥 = 87
Problem: other sample → other result
How can we use the idea of a sampling distribution to draw a conclusion about the
population based on one sample?
P-value:
A small p-value (typically ≤ 0.05) indicates strong evidence against the null
hypothesis, so you reject the null hypothesis.
A large p-value (> 0.05) indicates weak evidence against the null hypothesis, so you fail to
reject the null hypothesis.
Sampling distribution for the mean:
1. We expect variation between samples
a. Sampling error: Natural discrepancy (chance fluctuation) between sample
statistic and corresponding population parameter
2. Most means will be around 80
Conclusion hypothesis test:
- Provides the sample result sufficient evidence against H0 (same chips
consumption)?
- Yes, if H0 is true, a mean of 87 is very unlikely
- Reject H0 & accept H1
- We have sufficient evidence that people eating light chips eat more than
people eating regular chips
Hypothesis Testing step by step
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 or Stuvia-credit 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 soph_. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $5.50. You're not tied to anything after your purchase.