Matched pairs or independent/separate samples?

For each of the prompts below, decide whether the parameter of interest is a mean difference (matched pairs,) or a difference in means (independent samples,).

1.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.

Identify the: unit/case:parameter:

2.A study wants to determine how free Wi-Fi affects data usage on a long-distance bus ride.A group of nine busses traveling from State College to New York City were randomly assigned to give free Wi-Fi to passengers and another nine busses traveling the same route were randomly assigned to offer Wi-Fi for a one-time charge for its passengers. The study measured the amount of data used, in gigabytes, on each bus for the one trip to find out the average difference in the amount of data used based on if Wi-Fi is free or a paid service.

Identify the: unit/caseparameter:

3.A family with two siblings, an older brother and a younger sister, goes to Six Flags to enjoy a day of rides.After each ride, the grandfather asks the older brother and younger sister to rate the ride on a scale of 1 (hated it) to 5 (loved it).The grandfather, a retired statistics professor, wants to know if the rating from the brother is lower, on average, than the younger sister.

Identify the: unit/caseparameter: