Analysis necessary to reduce the concentration of PCBs

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Homework Help Overview

The discussion revolves around the analysis of PCB (polychlorinated biphenyls) concentrations in wastewater, specifically addressing whether the average concentration of 3.20 ppm from samples necessitates stopping production due to exceeding permissible limits.

Discussion Character

  • Exploratory, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants are examining statistical methods to determine if the average concentration indicates a need to halt production. Questions about what constitutes conclusive proof are raised, alongside calculations involving sample means and standard deviations.

Discussion Status

Some participants have provided calculations related to the statistical significance of the findings, while others seek clarification on the definition of conclusive proof in this context. The discussion is ongoing with various interpretations being explored.

Contextual Notes

The problem is framed within specific internal factory guidelines regarding PCB concentrations, and there is an emphasis on the implications of statistical analysis in decision-making processes.

jingjang
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Hello

i have a problem with my homework and i hope someone can help me? because i really don't know how to calculate this
so its translated with google translate :blushing:

Major customer PCB (polychlorinated biphenyls, a hazardous substance used in
manufacture of transformers and capacitors), bring in small quantities PCBja
wastewater environment. Permissible concentration in water PCBja standard 5ppm
(Parts per million). Factory Administration issued internal instructions that must be stopped
production if the average concentration in the effluent PCBja exceed 3 ppm. Analysis
effluent in 50 random samples taken showed an average of 3.20 ppm PCBs, with
0,23 scattering ppm (squared).
Calculate:
A: are the results of the analysis is conclusive proof that it is necessary to stop production
B: is based on the analysis necessary to reduce the concentration of PCBs in the effluent
C: if you were the head of the factory, what would be your action on the basis of the analysis carried out
 
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Please show us what work you have done on this problem, so that we can better help you. In particular, what do you think would constitute as conclusive proof?
 


n=50
x=3ppm
xi=3.2ppm
s2=0.23ppm2
s=0.48ppm
λ=(3.2ppm-3ppm)/0.48ppm=0.42

hmmm...
 


or is it like this
t=(3.2ppm-3ppm)/0.48ppm * √n =2.97
H(S=95%,n-1) x=μ--> t=2.0092
2.97<2.0092 (not true)
H(S=99%, n-1) x≠μ t=2.6802
2.97>2.6802 (true)
 

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