Statistic

hypothesis test for one population mean when sigma is known
- Z test
- assumptions:
- 1. Simple random Sample
- 2. sigma is known
- 3. normal or large distribution
test for 1 population mean when sigma is unknown
- T-test
- assumptions:
- 1.Simple random Sample
- 2. sigma is unknown
- 3. normal or large n
2 population mean when standard deviations are the same
- Pooled t-test
- If the large S divided by small S is less than 2 it is still pooled
- assumptions:
- 1. Simple random Sample
- 2. independent samples
- 3. same standard deviations
- 4. normal or large n
pooled t-interval

assumptions are the same for 2 population mean pooled t test
2 population means when standard deviations are not the same
- non pooled t test
- assumptions:
- 1.Simple random Sample
- 2. independent samples
- 3. standard deviations are not the same
- 4. normal or large n
paired t-test
- differences between populations make it a t test
- assumptions:
- 1. Simple random Sample
- 2. normal or large n
- null: mu1=mu2 (difference is 0)
- alternative: mu1 <,>,not = mu2
chi squared/ chi squared goodness of fit
- always right skewed
- assumptions:
- 1. all expected frequences are at least 1
- 2. at most 20% of expected frequencies are less than 5
- 3.Simple random Sample
- null: two variables are not associated
- alternative: they are associated

Author

starvinmarvin623

ID

120735

Card Set

Statistic

Description

statistics

Updated

2011-12-04T21:57:16Z

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