Answer:
Stratified sampling
Step-by-step explanation:
Samples may be classified as:
Convenient: Sample drawn from a conveniently available pool.
Random: Basically, put all the options into a hat and drawn some of them.
Systematic: Every kth element is taken. For example, you want to survey something on the street, you interview every 5th person, for example.
Cluster: Divides population into groups, called clusters, and each element in the cluster is surveyed.
Stratified: Also divides the population into groups. However, then only some elements of the group are surveyed.
In this question:
Population divided into groups, and random samples are drawn from the groups. This is a mark of stratified sampling.
97 rounds up to 100
78 rounds up to 80
100x80= 8,000
estimate=8,000
97x78=7,566
product=7,566
Answer:
138 is the answer
Step-by-step explanation:
128 square
X=hours of plan A
y=hours of plan B
wed: 5x+6y=12
thu: 3x+2y=6
so
5x+6y=12 and
3x+2y=6
we can eliminate y's by multiplying 2nd equation by -3 and adding to first equation
-9x-6y=-18
<u>5x+6y=12 +</u>
-4x+0y=-6
-4x=-6
divid both sides by -4
x=-6/-4
x=3/2
x=1.5
sub back
3x+2y=6
3(1.5)+2y=6
4.5+2y=6
2y=1.5
y=0.75
Plan A=1.5 hours
Plan B=0.75 hours
