The 99% confidence interval for the population mean is (20.6568, 29.3432)
In statistics, a confidence interval describes the likelihood that a population parameter would fall between a set of values for a given percentage of the time. Confidence ranges that include 95% or 99% of anticipated observations are frequently used by analysts. Therefore, it can be concluded that there is a 95% probability that the true value falls within that range if a point estimate of 10.00 is produced from a statistical model with a 95% confidence interval of 9.50 - 10.50.
Given:
Sample size = 21
Mean = 25
Standard deviation = 7
Confidence interval = 99%
α=1−0.99=0.01
α/2 = 0.005
Degrees of freedom(df)=n−1=21−1=20
Critical value(tc)=tα/2,df = t0.005,20 = 2.8433
Confidence Interval = mean +- tc * s/[tex]\sqrt{n}[/tex]
C.I = 25 ± 2.8433×7/[tex]\sqrt{21}[/tex]
C.I = (25 ± 4.3432)
C.I = (25−4.3432, 25+4.3432)
C.I = (20.6568, 29.3432)
99% confidence interval for the population average of the times homes are shown is (20.6568, 29.3432)
Learn more about confidence intervals:
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