{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

sta 2006 0809_lecturenotes_5

sta 2006 0809_lecturenotes_5 - Construction of Interval...

This preview shows pages 1–4. Sign up to view the full content.

Construction of Interval Estimators : pivot definition : A random variable Q ( X , θ ) is a pivotal quantity (or pivot) if the distribution of Q ( X , θ ) is independent of all parameters. Concepts 1. Interval width and precision 2. Confidence level (confidence coefficient) A. Confidence intervals for a normal mean 1. σ 2 known 2. σ 2 unknown 53

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

View Full Document
Example Let X equal the length of life of a 60-watt light bulb marketed by a certain manufacturer of light bulbs. Assume that the distribution of X is N ( μ, 1296). A random sample of n = 27 bulbs were tested until they burned out, yielding a sample mean of ¯ x = 1478 hours. Construct a 95% confidence interval for μ . 54
Example Let X equal the amount of butterfat (in pounds) produced by a typical cow during a 305-day milk production period between her first and second calves. Assume that the distribution of X is N ( μ, σ 2 ). To estimate μ a farmer measured the butterfat production for n = 20 cows yielding the following data: 481, 537, 513, 583, 453, 510, 570, 500, 457, 555, 618, 327, 350, 643, 499, 421, 505, 637, 599, 392 Construct a 90% confidence interval for μ .

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

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 12

sta 2006 0809_lecturenotes_5 - Construction of Interval...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online