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A student measured the lead content of a paint sample 4 times. The standard deviation of the measurements was found to be 0.76% of the average. Calculate the confidence interval at the 90% confidence level.

User Lko
by
6.6k points

1 Answer

6 votes

Answer:


CI =0.894%

Explanation:

From the question we are told that:

Sample size
n=4

Standard deviation
\sigma=0.76\% of \=x

Confidence level
\mu =90\%=0.90

Degree of Freedom
Df=n-1=3

Therefore

Test T from table is given


t=2.353

Generally the equation for Confidence interval CI is mathematically given by


CI =t*(\sigma)/(√(n))


CI =2.353*(0.76)/(√(4))


CI =0.894%

User Rashard
by
6.3k points
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