The effects of detergent brand nam e (factor A ) and the tem perature o f the w ater (factor B) on the brightness of washed fabrics are being studied. Four brand names and tw o tem perature levels are used, and six replicates for each com bination are examined. The follow ing ANOVA table is produced.

ANOVA Source of Variation SS df MS F p-value F crit Sample 75 1 75 63.38 8.92E-10 4.084 Columns 130.25 3 43.42 36.69 1.45E-11 2.839 Interaction 8.67 3 2.89 2.44 0.0783 2.839 Within 47.33 40 1.18 Total 261.25 47

a. Can you co nc lu d e th a t th e re is in tera ctio n b e tw e e n d e te rg e n t b ran d n a m e a n d th e te m p e ra tu re o f th e w a te r at th e 5 % significance level?

b. Are you able to cond uct tests based on th e m ain effects?

If yes, c o n d u c t th e s e tests a t th e 5 % significance level. If no, explain. P-69