Lecture9ch5

# Lecture9ch5 - STAT 350 LECTURE 9 Chapter 5(5.6 Describing...

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

STAT 350 L ECTURE 9 Chapter 5 (5.6) Describing Sample Distributions Central Limit Theorem

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

View Full Document
H OMEWORK #4 Chapter 5: 26, 30, 32, 34, 35(a)(c), 37, 42, 46
A PPROXIMATE S AMPLING D ISTRIBUTION (E XAMPLE 5.14) The weight of 50 lb of rice from a certain producer has a normal distribution with μ =50 (lb), σ =2(lb) Suppose we draw 1000 random samples, and each sample is of size n=25 If we calculate the mean of each sample, how many sample means do we get? We can plot the histogram of these sample means See Figure 5.14 on page 224

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

View Full Document
E XAMPLE 5.14
S AMPLING D ISTRIBUTION Which values of the sample mean are more likely to occur? (48.5,51.5)

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

View Full Document
S AMPLING D ISTRIBUTION Suppose we select a single sample of size 25 from a normal distribution with unknown μ and σ =2 If the sample mean is 50 for this sample: We can infer that the unknown mean μ (population mean) is almost certain to be in (48.5, 51.5) We can be reasonably confident that μ is (49, 51) Sampling distribution (of sample mean) make inferences about population parameter ( population mean μ )
G ENERAL P ROPERTIES OF S AMPLING D ISTRIBUTIONS The sampling distribution of a statistic often tends to be centered at the value of the population parameter The spread of the sampling distributions of many statistics tend to grow smaller as the sample size n increases As the sample size increases, sampling distributions of many statistics become more and more bell- shaped (normal distribution)

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.

## This note was uploaded on 04/23/2011 for the course STAT 350 taught by Professor Staff during the Spring '08 term at Purdue.

### Page1 / 19

Lecture9ch5 - STAT 350 LECTURE 9 Chapter 5(5.6 Describing...

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

View Full Document
Ask a homework question - tutors are online