Stat 344 Lecture 18 (17), Confidence Intervals for mean and proportion

Stat 344 Lecture 18 (17), Confidence Intervals for mean and proportion

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Concepts of Point Estimation Lecture 18 (former 17) Topics Basic properties of a confidence interval Large-sample confidence intervals Population mean for measurement data Population proportion for categorical data Bootstrap confidence intervals – ignore Confidence bounds Lecture 17 Reference: Devore Sec 7.1 Basic properties of confidence intervals Sec 7.2 Large-sample confidence intervals for the . 1 Stat 344 Lecture 17
Background image of page 1

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

View Full Document Right Arrow Icon
Point Estimates Point estimates of a population parameter are a single number (statistic) calculated from a sample. For the population mean => x-bar For the population proportion => p-hat A confidence interval is a range that has a given probability of including the true population parameter. A narrow interval has greater precision . The estimate of the Brand 1 parameter is more precise than that of 2. 2 Stat 344 Lecture 17
Background image of page 2
Confidence Interval of the Mean We desire to estimate the population mean (μ) Initial assumptions (to be removed later) : The population distribution is normal. The value of the population standard deviation is known. X-bar is the point estimate of μ The interval of the estimate for μ is X-bar ± the margin of error : 3 Stat 344 Lecture 17
Background image of page 3

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

View Full Document Right Arrow Icon
Interpretation About 95% of the intervals will include the population mean (per prior slide). X-bar is the random variable & center of the interval. The interval is X-bar ± margin of error. 10 of these 11
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 16

Stat 344 Lecture 18 (17), Confidence Intervals for mean and proportion

This preview shows document pages 1 - 5. Sign up to view the full document.

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