A research study begins by separating a sample of 40-year-old men into two groups: a high-income group and a low income group. A score measuring alcohol use is then obtained for each participant. The study intends to determine whether a relationship exists between income and alcohol use. This study is an example of the research strategy.

d

step-by-step explanation:

answer:  

step-by-step explanation:

here x represents the height of the pole,

and, the height of the shadow of the pole is 12 feet.

also, the angle of elevation from the top of the pole is 40°,

therefore,

by the low of sine,

which is the required equation for finding the value of x,

77

step-by-step explanation:

this is answer of 144 cubic meters