Which correlation coefficient represents the strongest downward trend in a data set? -0.83 -0.23 0.12 0.92

-0.83

Step-by-step explanation:

A correlation coefficient(r) is used to determine the strength and direction of the relationship between two variables.

-1 ≤ r ≤1

For downward trend r is negative.

For strong correlation r should be closer to 1 or -1.

From the given correlation coefficients  -0.83 is both negative and closer to -1.

Hence, a correlation coefficient represents the strongest downward trend in a data set = -0.83

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.

i hope this is what you were looking for.

see attached graph