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#### mikethepenguin

The data is below.

15, 16, 16,16, 17, 17, 17, 18, 18, 18, 18, 18, 19, 19, 19, 20, 21, 21, 21, 21,21, 21, 22, 22, 23, 23, 24, 25, 26, 26

Mean = 19.93

Variance 9.236781609

Standard deviation 3.039207398

95% confidence level (i used the t-table for this)2.045

Standard deviation/ Square root of (30) = 0.554880816

Confidence Interval (min, max)

= Mean - (2.045) * (0.5548)

=Mean + (2.045) * (0.5548)

18.79860206

21.0680646

The answers from Minitab are 18.3675, 21.5970

Can anyone help?