Given a sample of 28 observations with a sample mean of 21.1 and a sample standard...

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Given a sample of 28 observations with a sample mean of 21.1 and a sample standard deviation of 4.21, which of the following

math Statistics-And-Probability

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Answer 1

Answer #1

Solution:

Option a. (19.133, 23.067) is right answer

Explanation:
Given that
s = 4.21, n = 28, Mean x̅ = 21.1

df = n-1 = 28-1 = 27
Confidence interval = x̅ ± t_{α/2, df} * s/√n
Level of significance α = 0.02
t_{α/2, df} = Z_{0.01, 27} = 2.4727

Now CI = x̅ ± t_{α/2, df} * s/√n
= 21.1 ± 2.4727 * 4.21/√28
= 21.1 ± 1.9673
= (19.133, 23.067)
The confidence interval :
19.133 < μ < 23.067

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Answer 2

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