Question 1
To perform diagnostics on the consistency of a laboratory scale, multiple measurements are taken using a reference weight over the course of several days. The variance observed over 20 repeated measures is 248. What is a 99% confidence interval for the measurement variance of this scale?
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(122.129, 688.486)
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(11.051, 26.239)
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(117.809, 633.862)
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(174.034, 413.213)
Question 2
To perform diagnostics on the consistency of a laboratory scale, multiple measurements are taken using a reference weight over the course of several days. The variance observed over 20 repeated measures is 248. A 99% confidence interval for the measurement variance is (122.129, 688.486). Would it be reasonable to believe that the population variance is 670?
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No, because this value is too far above the sample variance of 248.
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Yes, because this value is within the 99% confidence interval.
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No, because a sample size of 20 is too small for estimation purposes.
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We cannot tell without more information.
A trilobite fragment (T) in a thin-section of an Ordovician limestone; E=echinoderm; scale bar is 2
Laboratory log
The Geologic Time Scale
Zone dimensions are not drawn to scale.
Human embryo at successive stages of development (not to scale).
The Geologic Time Scale