Which type of sampling method is being employed in the following example? a study is being conducted of all schools in gwinnett county. one student's parents from each school is randomly selected and asked in a survey what they think of gwinnett county public schools.

a simple random sampling

b stratified sampling

c cluster sampling

d sampling of convenience

e systematic sampling

Is there a direction u in which the rate of change of f(x,y)equals=x squared minus 3 xy plus 4 y squaredx2−3xy+4y2 at p(1,2) equals 14? give reasons for your answer. choose the correct answer below. a. no. the given rate of change is smaller than the minimum rate of change. b. no. the given rate of change is larger than the maximum rate of change. c. yes. the given rate of change is larger than the minimum rate of change and smaller than the maximum rate of change.