The art in scientific thinking is a. finding the right problem to study. b. deciding which assumptions to make. c. the ability to make an abstract subject easy to understand. d. not something in which economists have to be skilled.

The skeletal system performs a variety of functions that are crucial to maintaining life processes. what function is performed in the bone marrow, but not in the ossified bones of the skeleton? a oxygen transportation c mineral storage b. muscle attachment d red blood cell production

To answer this question, researchers studied populations of the dusky salamander (desmognathus ochrophaeus) living on different mountain ranges in the southern appalachian mountains. the researchers tested the reproductive isolation of pairs of salamander populations by leaving one male and one female together and later checking the females for the presence of sperm. four mating combinations were tested for each pair of populations (a and b)—two within the same population (female a with male a and female b with male b) and two between populations (female a with male b and female b with male a). the proportion of successful matings for each mating combination was measured. for example, when all the matings of a particular combination were successful, the researchers gave it a value of 1; when none of the matings were successful, they gave it a value of 0. then the researchers calculated an index of reproductive isolation that ranged from 0 (no isolation) to 2 (full isolation). the reproductive isolation value for two populations is the sum of the proportion of successful matings of each type within populations (aa + bb) minus the sum of the proportion of successful matings of each type between populations (ab + ba). the table provides data for the geographic distances and reproductive isolation values for 27 pairs of dusky salamander populations.

Astore manager timed janette to see how long it would take her to fold and put away a sweater, a shirt, a pair of pants, and a scarf. it took her 26.1 seconds for the shirt, 24.3 seconds for the sweater, 32.8 seconds for the pants, and 18.2 seconds for the scarf. what was the average time it took janette to fold and put away all four items? during a catered lunch, an average of 4 cups of tea are poured per minute. the lunch will last 2 hours. how many gallons of tea should the caterer bring if there are 16 cups in one gallon?