The Strength of a Weld Depends to Some Extent on the Metal

Essay

The strength of a weld depends to some extent on the metal alloy used in the welding process. A scientist working in the research laboratory of a major automobile manufacturer has developed three new alloys. In order to test their strengths, each alloy is used in several welds. The strengths of the welds are then measured, with the results shown below. Can the scientist conclude at the 5% significance level that differences exist among the strengths of the welds with the different alloys? $$\begin{array} { | c | c | c | } \hline & { \text { Strenghh of welds } } \\\hline \text { Alloy 1 } & \text { Alloy } 2 & \text { Alloy } 3 \\\hline 15 & 17 & 25 \\\hline 23 & 21 & 27 \\\hline 16 & 19 & 24 \\\hline 29 & 25 & 31 \\\hline & 28 & 23 \\\hline & 19 & \\\hline\end{array}$$