Activity 1: Matched pairs or independent/separate samples? For each of the prompts below, decide whether the parameter of interest is a mean difference (matched pairs, μ_d) or a difference in means (independent samples, μ_1- μ_2). Students want to know if it matters where they have their cell phone screen repaired. A sample of eight cell phones with broken screens was obtained. For each phone, an estimate for the screen repair in U. S. dollars ($) was obtained from a local store, where the phone would be dropped off and picked up, and from an on-line merchant, where the phone needs to be shipped to a national chain and shipped back. Your goal is determining if, on average, the estimate in dollars for the total repair from the on-line merchant is more (possibly because of the added cost of shipping) than the estimate from a local store.