MakingDecisions07A

MakingDecisions07A - Making decisions based on a...

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

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

View Full Document

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.

Unformatted text preview: Making decisions based on a statistical sample ESM 206A Nov 7 2007 Environmental challenge The problem: Athington Park House is a very desirable property that was built some years before the discontinuing of lead in paint in the mid-1970s. A prospective buyer is concerned about the possible presence of lead in dust contained in the house. Dust sampling offers a way of characterizing dust lead levels at a property and determining if intervention is warranted. One of the preferred methods for sampling residential dust is using baby wipes to wipe a specified surface area. A single area may be sampled using an individual wipe; or multiple areas of a room may be sampled with individual wipes, and the individual wipes combined, or composited, then submitted to the laboratory as a single sample. The EPA proposed standard stated that if dust lead levels were above 50 g/ft 2 on bare floors, a lead health hazard was possible and follow-up testing and/or intervention should be undertaken (40 CFR 745). Your job: Design a sampling scheme and analysis procedure such to decide whether to do intervention. Hypothesis tests of sample means Statistical theory says: If the population is normally distributed, and the population mean is , then the quantity is normally distributed with mean zero and variance one But we dont know Statistical theory also says that the quantity follows a t distribution with = n-1 degrees of freedom n x / - / x X x x x t s s n -- = = T DISTRIBUTION Similar to Normal Distribution Requires degrees of freedom.Requires degrees of freedom....
View Full Document

This note was uploaded on 08/06/2008 for the course ESM 206 taught by Professor Kendall,berkley during the Spring '08 term at UCSB.

Page1 / 16

MakingDecisions07A - Making decisions based on a...

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

View Full Document
Ask a homework question - tutors are online