A thread manufacturer was interested in how many breaks in thread occurred for four winding speeds (Slow, Normal,Fast, Maximum). The number of breaks for 10,000 spools was recorded. Diagnostic plots are below.

(a)Based on the plots, does it appear as though the assumptions for ANOVA are met? Explain.

(b)State the null and alternative for the Shapiro-Wilks test.

(c)State the null and alternative for the Brown-Forstyhe test.

(d)The p-value for the hypothesis of equal means on this data was: 7.593X10^-16. Do you believe it is reliable? Explain.

Errors vs. Group Means Normal Q-Q Plot Histogram of errors . . . . . . . Errors O . . . . . . . . . Sample Quantiles Frequency ... -10 O 6 8 10 12 14 16 -2 -1 0 2 -10 -5 0 10 Group Means Theoretical Quantiles e_ij (in number of breaks)