An important feature of digital cameras is battery life, the number of shots that can be taken before the battery needs to be recharged. The file DigitalCameras contains the battery life of 29 subcompact cameras and 16 compact cameras. (Data extracted from "Digital Cameras," Consumer Reports, July 2009, pp. 28-29.)
a. Assuming that the population variances from both types of digital cameras are equal, is there evidence of a difference in the mean battery life between the two types of digital cameras (α = 0.05)?
b. Determine the p-value in (a) and interpret its meaning.
c. Assuming that the population variances from both types of digital cameras are equal, construct and interpret a 95% confidence interval estimate of the difference between the population mean battery life of the two types of digital cameras.