factor

mean

standard deviation

sample size

confidence level

confidence interval

u₁

1.30

0.732695097

20

0.90

1.3 ± 0.29

u₂

3.60

0.940324692

20

0.90

3.6 ± 0.37

u₃

2.70

1.750187960

20

0.90

2.7 ± 0.68