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Statistical Inference

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Presentation on theme: "Statistical Inference"— Presentation transcript:

1 Statistical Inference
Introduction to Statistical Inference

2

3 1 We observed !

4 What is the true value of p , in the experiment ?
Is exact value of ? No

5 Plausible range that will be in ?
(0, 1) : true but no meaning A reasonable way is How to take the value ?

6 Is the statement right ? How can we decide the answer ?

7 statistic vs. parameter
sample population statistic vs. parameter

8 Parameter characterizes the population
8

9 Statistic is a function of a sample.

10 Statistic

11 sample mean, sample median & sample variance
11

12 (o) 12

13 (X) is neither parameter nor statistic (X) (o) 13

14 non-parametric question vs. parametric question
What is the population ? What is and ? non-parametric question vs. parametric question 14

15 Answer the following questions
by using the information obtained from the sample. A: What is ? B: What is the plausible range for ? C: Is true ? 15

16 We have a random sample obtained from What is ? estimator 16

17 17

18 18

19 ?

20 ? 1 2 3 4 5 6 1/6

21 1 2 3 4 5 6 1 2 3 4 5 6 1.5 2.5 3.5 4.5 5.5

22 Sampling distribution:
the distribution that a statistics follows.

23 1 2 3 4 5 6 0.00 0.05 0.10 0.15 0.20 0.25 0.30 n = 8

24 24

25 25

26 26

27 27

28 Why (n-1) ? 28

29 Which one is better ?

30 for large

31

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33 For an estimator, if the mean of the sampling distribution
of the estimator is equal to the parameter, then the estimator is called unbiased; otherwise biased. 33

34 unbiased! unbiased! 34

35 35

36 biased ! 36

37 unbiased! unbiased! 37

38

39 Strong Law of Large Numbers (SLLN)

40 X

41 Central Limit Theorem (CLT)

42

43 Thank you !!


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