Degrees of freedom = n – 1 = 13 – 1 = 12
Margin of error = t(α,v) *S /sqrt(n)
Margin of error = 1.35025
1.35025 = t*2.546239/sqrt(13)
1.35025 = t*0.7062
t = 1.35025/0.7062
t = 1.911994
t = 1.912
df = ν = 13-1
df=12
So, α = 0.04
(by using given table)
k = (1 – α) 100 %
k= (1 – 0.04) 100 %
k = 0.96 or
K=96%
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