The article "Withdrawal Strength of Threaded Nails" (D. Rammer, S. Winistorfer, and D. Bender, Journal of Structural Engineering, 2001:442–449) describes an experiment comparing the withdrawal strengths for several types of nails. The data presented in the following table are consistent with means and standard deviations reported in the article for three types of nails: annularly threaded, helically threaded, and smooth shank. All nails had diameters within 0.1 mm of each other, and all were driven into the same type of lumber. Nail Withdrawal Strength (N/mm) Type Annularly 36.57 29.67 43.38 26.94 12.03 21.66 41.79 31.50 35.84 40.81 threaded Helically 14.66 24.22 23.83 21.80 27.22 38.25 28.15 36.35 23.89 28.44 threaded Smooth 12.61 25.71 17.69 24.69 26.48 19.35 28.60 42.17 25.11 19.98 shank Construct an ANOVA table. You may give a range for the P-value. Can you conclude that the mean withdrawal strength is different for different nail types? a. b.

a) which for these data is 32.1470, 42.3520, or 10.0674 c) that minimizes the error sum of squares, total sum of squares, or regression sum of squares…for which these data is 32.1470, 42.3520, or 10.0674

Given the linear correlation coefficientr and the sample size n, determine the critical values of r and use your finding to state whether or not the given r represents a significant linear correlation. Use a significance level of 0.05. r = 0.353, n = 15 O A) Critical values: r = +0.532, no significant linear correlation B) Critical values: r = 0.514, no significant linear correlation C) Critical values: r = ±0.514, significant linear correlation D) Critical values: r = ±0.514, no significant linear correlation

Three different methods for assembling a product were proposed by an industrial engineer. To investigate the number of units assembled correctly with each method, 30 employees were randomly selected and randomly assigned to the three proposed methods in such a way that each method was used by 10 workers. The number of units assembled correctly was recorded, and the analysis of variance procedure was applied to the resulting data set. The following results were obtained: SST =10,870; SSTR =4580. a. Set up the ANOVA table for this problem (to 2 decimals but p-value to 4 decimals, if necessary). Source of Variation Sum of Squares Degrees of Freedom Mean Square F p-value Treatments 4580 Error 6290 Total 10870 b.Use a = 0.05 to test for any significant difference in the means for the three assembly methods. Calculate the value of the test statistic (to 2 decimals). The p-value is - Select your answer - What is your conclusion? Select your answer -