Digital cameras have taken over the majority of the point-and-shoot camera market. One of the important features of a camera is the battery life as measured by the number of shots taken until the battery needs to be recharged. The data in the file Digital cameras contain the battery life of 31 subcompact cameras and 15 compact cameras (data extracted from "Cameras," Consumer Reports, November 2006, pp. 20-21).
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.