To assess the reliability of timber structures and related building design codes, many researchers have studied strength factors of structural lumber. In one such study (“Size Effects in Visually Graded Softwood Structural Lumber,” J. of Materials in Civil Engr., 1995: 19–29), three species of Canadian softwood were analyzed for bending strength. Because the amount of bending depends on the width and length of a board and the particular stress applied, the board dimensions were kept the same in each of the three wood species. Wood samples were selected from randomly selected sawmills, and, according to ASTM Standard D 4761, each sample was conditioned by kiln and air drying to achieve approximately a 15% moisture content. The results of the experiment are given here.
Using a significance level of 5%, conduct an ANOVA test to determine whether there is a difference in the mean bending strengths among the three types of wood.