z-test y-yesy central limit theorem
Storyboard Text
- Glida: 1
- While this knife is a Central Limit theorem, some pieces might be big, some small, but the more I chop, the more they average out to a uniform size.
- Oh! Central Limit Theorem is that no matter how the data looks at first, with at least 30 samples, the averages form a normal distribution!
- Exactly! Whether variance is known or unknown, we can still use the Z-test, replacing the population's standard deviation with the sample's in the formula.
- Glida: 2
- Now let's test your knowledge! A company claims their chocolate bars weigh exactly 50 grams. The standard deviation of their chocolate bars is known to be 5 grams. A food inspector randomly selects 100 bars and finds their average weight is 48 grams.
- The sample size is 100 and the population standard deviation known is 5 grams.
- Then the appropriate test statistic to to be used is Z-test.
- Glida: 3
- So samples help us understand populations, and different tests help us analyze them.
- And choosing the right test is like picking the right recipe—it makes all the difference!
- Great job, kids! Before anything else, let’s go over the key ingredients of statistics!A population includes all data points, while a sample is a smaller subset. The sample mean (x̄) estimates the population mean (μ), and when the sample is large and random, it provides a reliable estimate. The population standard deviation (σ) measures overall variability, while the sample standard deviation (s) estimates it from a subset. Population variance (σ²) shows data spread across the population. A test statistic is a value calculated from sample data to compare results with expectations under the null hypothesis in hypothesis testing.
Över 30 miljoner storyboards skapade
Inga Nedladdningar, Inget Kreditkort och Ingen Inloggning Behövs för att Prova!
