## A journal article reports that a sample of size 5 was used as a basis for calculating a 95% CI for the true average natural frequency (Hz) o

Question

A journal article reports that a sample of size 5 was used as a basis for calculating a 95% CI for the true average natural frequency (Hz) of delaminated beams of a certain type. The resulting interval was (230.061, 233.807). You decide that a confidence level of 99% is more appropriate than the 95% level used. What are the limits of the 99% interval?

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2 weeks 2021-10-12T09:40:00+00:00 1 Answer 0

(229.5450, 234. 3230)

Step-by-step explanation:

Given that a  journal article reports that a sample of size 5 was used as a basis for calculating a 95% CI for the true average natural frequency (Hz) of delaminated beams of a certain type.

95% confidence interval was From confidence interval we find mean as the average of lower and upper bound.

Mean = Margin of error = upper bound -mean

= i.e. 1.96 * std error = 1.873

For 99% interval margin of error would be 2.58*std error

so margin of error for 99% = Confidence interval 99% lower bound = Mean – 2.3890 =229.5450

Upper bound = Mean +2.3890 = 234.3230