Dr. ramos is interested in studying how indoor lighting can influence people's moods during the winter. a sample of 100 households is selected. fifty of the homes are randomly assigned to the bright-light condition where dr. ramos replaces all the lights with 100-watt bulbs. in the other 50 houses, all the lights are changed to 60-watt bulbs. after two months, dr. ramos measures the level of depression for the people living in the houses. assuming that the study uses people from different age groups, participant age would be a(n) variable in the experiment.

Jack owns a small home near a school. he doesn't have any children, and doesn't plan on having any in the future. jack is a writer and works out of his home. all of the noise from the playground during the day interrupts jack while he is trying to work. tina, a friend of jack's, also owns a small home. her home is in a quiet, little secluded neighborhood. she has a child that will be entering first grade in the fall and wishes she lived closer to a school. one day, jack asked tina if she would want to exchange homes. is this a possibility? a. yes, a trade of properties (exchange) is possible if the trade involves no financing and the properties are not mortgaged. b. yes, a trade of properties (exchange) is possible if the trade involves no financing. c. no, it is not a possibility. simply "trading" real estate is not recognized under california real estate law. d. none of the above