Ch08_2 - Chapter 8 Part II Confidence Intervals Chapter 8 1...

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

View Full Document Right Arrow Icon
Chapter 8 1 Chapter 8 Part II Confidence Intervals
Background image of page 1

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

View Full DocumentRight Arrow Icon
Confidence Intervals For population mean Standard deviation known (z) Standard deviation unknown (t) For a proportion (z) Find correct sample size for given error For population mean For proportion
Background image of page 2
Chapter 8 3 X = monthly cell phone minutes Suppose we don’t know μ . σ = 115.4 A simple random sample with n = 35 had an 553.4 minutes x =
Background image of page 3

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

View Full DocumentRight Arrow Icon
Chapter 8 4 What do we know? μ -38.24 μ+38.24
Background image of page 4
Chapter 8 5 CI for population mean Confidence interval estimate for μ : Where α /2 is the upper tail area of the standard normal curve. x z n ± α σ /2 Margin of error
Background image of page 5

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

View Full DocumentRight Arrow Icon
Chapter 8 6 We can say that has a 95% chance of being within 38.24 minutes of the true value of μ . In other words, 95 out of 100 samples will have a sample mean within 38.24 minutes of μ . x
Background image of page 6
7 Regarding this specific sample mean: = 553.4 so we are 95% confident that the true value of μ is between 553.4-38.24 and 553.4+38.24. This is called a
Background image of page 7

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

View Full DocumentRight Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 12/13/2010 for the course LEEDS BCOR 1020 taught by Professor Heatheradams during the Spring '08 term at Colorado.

Page1 / 22

Ch08_2 - Chapter 8 Part II Confidence Intervals Chapter 8 1...

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