slide2_1 - 1 Parameter estimation: example Suppose that out...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 1 Parameter estimation: example Suppose that out of 1 million relays exactly 2.5% (or 25000) are defective, but we do not know that. We would like to estimate that percentage by inspecting a relatively small sample. What should we do? Lets simulate random sampling from that populaton (can use Excel). 2 Estimation of proportion Large population of objects Every object can be defective with probability of p independently of the other objects We can select a sample of size n from the population How can we estimate p from the sample? 3 Example 1 The 1700 ship insurer knows out of 755 ships that sailed from the local port 10 were lost at sea. What is the point estimate of the probability p that a ship can be lost at sea? p 4 Example 2 A company wants to estimate the percentage of defective (out of spec) shafts produced by a new super-fast technology. The trial run of 500 shafts ended up in 3 of them being out of spec. What is the point estimate of the proportion of defective shafts for this process? 5 Point estimator of proportion Sample of size n was taken The number of defective items in the sample is X Then the point estimator of the proportion of defective is n X p = 6 Why this estimator Unbiased estimator: In other words, the long run average of the estimated proportion is the true one p n np n X E p E = = = ) ( ) ( 7 Parameter estimation: example 2 A machine is producing shafts with the mean diameter 0.512 mm and the standard deviation of 0.015 mm (and approximately normally distributed)...
View Full Document

This note was uploaded on 03/17/2008 for the course IE 121 taught by Professor Perevalov during the Spring '08 term at Lehigh University .

Page1 / 31

slide2_1 - 1 Parameter estimation: example Suppose that out...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online