4. Among the probability and nonprobability sampling techniques we learned in class, identify the sampling technique and describe the advantages and limitations of each technique. a) The names of all 1,000 children are placed into a computer database. The computer is then instructed to randomly select 100 names. These children and their parents are then contacted. b) The names of all 1,000 children are placed into a computer database and organized by grade (6th, 7th, and 8th). The computer is then instructed to randomly select 35 names from each of the three grades. These children and their parents are then contacted. c) The researcher knows one of the middle school teachers, and the teacher volunteers her 35 students for the study. These children and their parents are then contacted. d) Using middle-school directory, the researcher selects the first twenty 6th grade boys, the first twenty 6th grade girls, the first twenty 7th grade boys, the first twenty 7th grade girls, the first twenty 8th grade boys, and the first twenty 8th grade girls. These children and their parents are then contacted.

v = 1/3 a^2h

step-by-step explanation:

if the height is 57.7cm and the height of the slant edge is 18.2cm, then the volume is 1/3 a^2h.

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.

step-by-step explanation:

one of the most important purposes of surface treatment is to alter surface properties according to the requirement of specific applications. for example, hydrophobic coating has been utilized on windshield and eyeglasses. gold atom monolayer on substrate has become a popular surface bioconjugation strategy.  

wait nvm i know the correct answer now its 100%   81 square feet

~batmans wife dun dun