The Amount of Lateral Expansion (Mils) Was Determined for a Sample

Essay

The amount of lateral expansion (mils) was determined for a sample of n = 9 pulsed-power gas metal arc welds used in LNG ship containment tanks. The resulting sample standard deviation was s = 2.80 mils. Assuming normality, derive a 95% CI for $\sigma ^ {2 }$ and for $\sigma$ .