Which of the following statements represents a difference between a sample survey and an observational study? a) presence of population. b)inclusion of numerical data. c)people are aware that they are participating. d)ability to collect information.

c seems most likely from the given answers

Step-by-step explanation:

C) People are aware that they are participating.

The sample survey is the technique which is initiates after taking proper consent from the participants by explaining the purpose of study and then data is collected which can be in the form of output of measurements, opinion about a cause or issue. But the observational study does not explain the purpose of the study to the participants, it just involves the data collection.

Therefore, on the basis of the above description, People are aware that they are participating. is the relevant option.

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.

idk wbu

step-by-step explanation: