Fundamentals of Probability and Statistics for Engineers

(John Hannent) #1

We thus have


These values are indicated in the third column of Table 10.3.
Column 5 of Table 10.3 gives


With k 7, the value of^2 k1,^2 is found from Table A.5 to be


2

Since d^2 6, 01 , the hypothesis is rejected at the 1% significance level.


10.2.2 The Case of Estimated Parameters

Let us now consider a more common situation in which parameters in the
hypothesized distribution also need to be estimated from the data.
A natural procedure for a goodness-of-fit test in this case is first to estimate
the parameters by using one of the methods developed in Chapter 9 and then to
follow the^2 test for known parameters, already discussed in Section 7.2.1. In


Table 10.3 Table for^2 test for Example 10.2

x 0 5147 0.6188 4853 5459
0 < x 1 1859 0.2970 2329 1484
1 < x 2 595 0.0713 559 633
2 < x 3 167 0.0114 89 313
3 < x 4 54 0.0013 10 292
4 < x 5 14 0.0001 1 196
5 < x 6 0.0001 1 36
7842 1.0 7842 8413
Note: ni, observed number of occurrences; pi,
theoretical P(Ai).

322 Fundamentals of Probability and Statistics for Engineers


P…Ai†ˆpiˆ

… 0 : 48 †i^1 e^0 :^48
…i 1 †!

; iˆ 1 ; 2 ;...; 6 ;

P…A 7 †ˆp 7 ˆ 1 

X^6

iˆ 1

pi;


Xk

iˆ 1

n^2 i
npi

nˆ 8413  7842 ˆ 571 :

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Interval,Ai ni pi npi n^2 i/npi

     

6, 0 01

6 0 01ˆ16 812

:

;: : :

0 :


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