A random sample of magnesium concentrations in parts per million, or ppm) in ground water from various locations follows. Estimate the mean concentration of magnesium in
ppm with 90% confidence. Assume o = 19.
101 64 74 94 105
101 95 36 34 34
61 60 116 74 119
9 16
30 82
20 69 78 63
42
86 118 116
75
46
79 40 110 79 61