Wanting to study the effect of exercise on preventing the common cold, a researcher collects 500 test subjects and randomly assigns them to a treatment group instructed to exercise and a control group instructed to not exercise. He later records the number of colds for each group. This is an example of: Group of answer choices linear regression independence an observational study an experiment

step-by-step explanation:

answers available in this download

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whole number data type

step-by-step explanation:

as whole number type represents whole number

like 1, 2 ,3, 4

in other words the whole numbers are those numbers which cannot be written infraction.

since we can take days as a whole number i.e 1 day 2 day and we cannot write 1.2 day hence we will use whole number data type

large crystals result from very slow cooling.

evaporation of water: this would produce an evaporite which is a sedimentary rock. like a salt pan in a desert. not possible to have volcanic rocks originate this way.

crystalization in molten earth: slow cooling over time. (hundreds to millions of years)

crystalization at earth's surface: this results in fast cooling. (a few hours to a few months or years)

crystalization from cooling off hot water: that would be a hydrothermal deposit. while associated with volcanics they are not volcanic rocks themselves and usually occur fairly rapidly.