=+41. Tablet computers. In July 2013, cnet.com listed the battery life (in hours) and screen size (in inches) for a sample of tablet computers. We want to know if screen size

(in inches) is associated with battery life. (reviews.cnet.

com/8301-19736_7-20080768-251/cnet-updates-tablet-te stresults/?tag=contentBody;contentHighlights)

Dependent variable is Video battery life (in hours)

R-squared = 3.37%

s = 2.32 with 37 - 2 = 35 degrees of freedom Coefficients Standard Error t Stat P-value Intercept 6.415803 2.319593 2.765918 0.009002 Screen Size 0.288758 0.261116 1.105861 0.27633 0

5 10 15 0 5 10 15 Baerie Life Screen Size Batterie Life Linear (Batterie Life)

–6

–4

–2 0

2 4

6 8 8.5 9 9.5 10 Residuals Predicted battery life Residuals

–4 –3 –2 –1 01234 More 0

2 4

6 8

Frequency Residuals M15_SHAR8696_03_SE_C15.indd 535 14/07/14 7:30 AM 536 CHAPTER 15 Inference for Regression