95% Confidence Interval
X̅ ± t(α/2, n-1) S/√(n)
t(α/2, n-1) = t(0.05 /2, 24- 1 ) = 2.069
80.3 ± t(0.05/2, 24 -1) * 23.6/√(24)
Lower Limit = 80.3 - t(0.05/2, 24 -1) 23.6/√(24)
Lower Limit = 70.3
Upper Limit = 80.3 + t(0.05/2, 24 -1) 23.6/√(24)
Upper Limit = 90.3
70.3 < < 90.3
Since 104 does not contain in confidence interval, the drug appear to be effective.
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