Why will random samples from a given population not have the same mean?
a-sample means will vary because the data values selected for samples are not randomly chosen.
b-sample means will vary because for each sample the same data values are selected.
c-sample means will vary because the data values are randomly selected from different populations.
d-sample means will vary because the data values selected for each sample will be different.

the answer is D

Step-by-step explanation:

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.

let y equal to

the total fare and x is the mile of taxi ride. so the equation is

y = 0.55x + 1.75

since susie has

$10 to spend for a taxi cab, so he can have

10 = 0.55x +

1.75

x = 15 miles of

taxi ride

so the system of

inequality is

10 < 0.55x +

1.75

x > 2