The following data represent the concentration of dissolved organic carbon​ (mg/L) collected from 20 samples of organic soil. Assume that the population is normally distributed. Complete parts​ (a)...

The following data represent the concentration of dissolved organic carbon​ (mg/L) collected from 20 samples of organic soil. Assume that the population is normally distributed. Complete parts​ (a) through​ (c) on the right.

Construct an 80​% confidence interval for the population mean μ.

11.40
8.81
30.91
19.80
29.80
11.90
14.86
14.86
27.10
20.46
20.46
8.09
16.51
14.90
15.35
17.50
5.20
33.67
9.72
18.30