Twelve samples of water from a particular source have an average lead concentration of 12.5μg/L with...

Twelve samples of water from a particular source have an average lead concentration of 12.5μg/L with a standard deviation of 2.0μg/L. The 95% confidence interval for the lead concentration in water from this source is approximately

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Expert Solution

We have given that,

Sample mean =12.5 μg/L
Sample standard deviation =2 μg/L
Sample size =12
Level of significance=0.05
Degree of freedom =11

t critical value is (by using t table)=2.201

Confidence interval formula is

=(11.2,13.8)


Lower confidence limit=11.2 μg/L

Upper confidence limit=13.8 μg/L

orchestra answered 1 year ago

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