Question

An article describes an experiment in which several types of boxes were compared with respect to compression strength (lb). The table below presents the results of a single-factor ANOVA experiment involving I = 4 types of boxes. Type of Box Compression Strength (lb) Sample Mean Sample SD 1 655.5 788.3 734.3 721.4 679.1 699.4 713.00 46.55 2 789.2 772.5 786.9 686.1 732.1 774.8 756.93 40.34 3 737.1 639.0 696.3 671.7 717.2 727.1 698.07 37.20 4 535.1 628.7 542.4 559.0 586.9 520.0 562.02 39.87 Suppose that the compression strength observations on the fourth type of box had been 654.1, 747.7, 661.4, 678.0, 705.9, and 639.0 (obtained by adding 119 to each previous x4j). Assuming no change in the remaining observations, carry out an F test with α = 0.05. State the appropriate hypotheses. H0: μ1 = μ2 = μ3 = μ4 Ha: all four μi's are unequal H0: μ1 = μ2 = μ3 = μ4 Ha: at least two μi's are unequal H0: μ1 ≠ μ2 ≠ μ3 ≠ μ4 Ha: all four μi's are equal H0: μ1 ≠ μ2 ≠ μ3 ≠ μ4 Ha: at least two μi's are equal Correct: Your answer is correct. Calculate the test statistic. (Round your answer to two decimal places.) f = 2.74 Incorrect: Your answer is incorrect. What can be said about the P-value for the test? P-value > 0.100 0.050 < P-value < 0.100 0.010 < P-value < 0.050 0.001 < P-value < 0.010 P-value < 0.001 Correct: Your answer is correct. State the conclusion in the problem context. Fail to reject H0. There is a difference in compression strengths among the four box types. Fail to reject H0. There is not a difference in compression strengths among the four box types. Reject H0. There is not a difference in compression strengths among the four box types. Reject H0. There is a difference in compression strengths among the four box types.

Answer 1