Which of the following characteristics of experiments are also characteristics of surveys?
Check all that apply.
I A. The study involves one or more treatment groups and a control
group.
B. Replication with different groups of subjects can improve the
reliability of the study.
I c. Data are gathered during the course of the study.
D. The study compares two or more treatments (possibly including
"no treatment").
O E Statistical analysis is applied to the results of the study.
SUBMIT

i wish i could u

step-by-step explanation:

i wish i could u

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.

80 the answer is 80

step-by-step explanation:

34.5 cm

step-by-step explanation:

generally for a circular segment of angle, θ° and radius r

arc length

= (θ/360) x circumference

= (θ/360) x 2πr

in our case, θ = 60°, π=3.142 and r = 33 cm

substitute into above formula

arc length

= (60/360) x 2(3.142)( 33) = 34.5 cm