An important feature of tablets is battery life, the number

of hours before the battery needs to be recharged. The file Tablets

WiFi Only3G/4G+WiFicontains the battery life of 12 WiFi-only and 7 3G/4G/WiFi

12.4011.709- through 12-inch tablets.

10.6011.40

11.5010.70a. Assuming that the population variances from both types of

12.6011.50tablets

8.0011.30are equal, is there evidence of a difference in the mean

10.9011.60battery life between the two types of tablets? 1Use a = 0.05.2

11.608.90b. Determine the p-value in (a) and interpret its meaning.

10.00c. Assuming that the population variances from both types of

10.90tablets

8.90are equal, construct and interpret a 95% confidence

9.50interval

10.50estimate of the difference between the population mean

battery life of the two types of tablets.