An experiment was conducted to study the life (in hours) of two different brands of batteries in three different devices (radio, camera, and portable DVD player). A completely randomized two-factor factorial experiment was conducted and the following data resulted.

Device Brand of Battery Radio Camera DVD Player A 8.6 7.9 5.4 8.2 8.4 5.7 B 9.4 8.5 5.8 8.8 8.9 5.9

(a) Analyze the data and draw conclusions, using

???? = 0.05.

(b) Investigate model adequacy by plotting the residuals.

(c) Which brand of batteries would you recommend?