The difference between an observational study and an experiment is that
O
O
O
in an observational study, only one-nup is studied, and in an experiment, two groups are studied.
in an observational study, the resea. chers do not control treatment, and in an experiment, they do.
in an experiment, cause-and-effect is analyzed, and in an observational study, it is not.
in an experiment, one group is studied over a short period of time, and in an observational study, the group is studied over
a longer period of time.

13

step-by-step explanation:

169-1=168

168-3=165

165-5=160

160-7=153

153-9=144

144-11=133

133-13=120

120-15=105

105-17=88

88-19=69

69-21=48

48-23=25

25-25=0

since it took 13times to completely subtract it hence its square root is 13

the correct option is 2.

step-by-step explanation:

according to the given information triangle abc is a right angle triangle with right angle at a. segment ab is 5 and segment ac is 7. point d is on segment bc and angles adb and adc are right angles.

it is given that triangles abd, cad, and cba are similar.

two triangles are similar if their corresponding sides are proportional.

in triangle cba, using pythagoras theorem

                      )

triangle abd and cba are similar,

                            (2)

triangle cad and cba are similar,

                      )

using (1), (2) and (3), we get

hence proved.

therefore option 2 is correct.

answer: idk wbu

step-by-step explanation: umm..

c-   36

taxicab circle radius 9 has 4(9) = 36 points