Lecture 7 Flashcards
1
Q
Statistical Methods
A
Data Collection Organization and Presentation Descriptive Measures Statistical Inference Predictive Statistics
2
Q
When is sample size large?
A
n = 30
3
Q
Sampling Distribution
A
Probablity Distribution of a statistic
4
Q
Two properties of good point estimators
A
The point estimator should be unbiased
The point estimator should have minimum variance
5
Q
Type 1 Error
A
Rejecting a null hypothesis when it is acceptable
Alpha error
False positive
6
Q
Type 2 Error
A
Failing to reject
Accepting a null hypothesis when it is false
Beta error
False negative
7
Q
Two situations in hypothesis testing
A
Case I: when variance is known
Case II: when variance in unknown
8
Q
Central Limit Theorem
A
When the sample size is large, distribution of sample means always follows a normal distribution
9
Q
T-Distribution
A
Used when population variance is unknown or when the sample size is small
