A laboratory work was conducted to determine the effect of certain metal treatment on the amount of material removed in a pickling operation. Initially, a random sample of 20 pieces was immersed in a...

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Extracted text: A laboratory work was conducted to determine the effect of certain metal treatment on the amount of material removed in a pickling operation. Initially, a random sample of 20 pieces was immersed in a bath for 24 hours without the treatment and another 40 samples was exposed to the treatment, followed by the same 24-hour immersion bath. No treatment sample yielded an average of 6.5 millimetres of metal removed with 1.1 standard deviation. The treated sample yielded an average of 4.5 millimetres metal removal with 0.9 standard deviation. i. At 95% confidence interval, prove if there is a difference between the two samples? i. At 98% confidence interval, illustrate if the same conclusion be made to 100 non-treated pieces' sample which yields an average of 12.2 millimetres of material removed, and 200 treated samples which yields an average of 9.1 millimetres, both with similar standard deviations, 1.1 and 0.9 respectively. ii. From (i) and (ii), determine if the treatment be used to protect metal from corrosion?