Dr. williams conducted a survey in the mall, measuring the shopping habits of people ages 15, 25, 35, 45, and 55, with 10 people in each group. which of the following best describes her study? an experiment a cross-sectional study a case study a longitudinal study a double-blind study

A cross-sectional study

Explanation:

The best fit would be cross-sectional study, for one because it is observational, meaning there is no manipulation of variables like you would find in an experiment. Secondly, it is comparing populations within different groups, in this case age groups. Although, this can also be done through a longitudinal study, but as the name suggests, it is longitudinal so it is done over longer periods of time.

light-year  

the distance that light travels in a vacuum in one year, equal to about 9.46 trillion km (5.88 trillion mi). light-years are used in measuring interstellar and intergalactic distances.  

parsec  

a unit of distance used in astronomy, equal to about 3.25 light years (3.08 × 1016 meters).  

parallax  

the apparent angular displacement of a celestial body due to its being observed from the surface instead of from the center of the earth (diurnal parallax or geocentric parallax) or due to its being observed from the earth instead of from the sun (annual parallax or heliocentric parallax)  

absolute magnitude  

the magnitude (brightness) of a celestial object as it would be seen at a standard distance of 10 parsecs.  

apparent magnitude  

the magnitude of a celestial object as it is actually measured from the earth.  

redshift  

an increase in the wavelength of radiation emitted by a celestial body as a consequence of the doppler effect.  

the great thing about your imagination is that it doesn't have to make sense! if i were you i would be stuck in space, no communication with earth travelling around and around, you can only guess how long its been since your communication broke down. you land on an undiscovered planet, you do a scientific investigation examining the elements and conditions. you come across alien lifeforms.  

best of luck!