A cluster sample is one in which the population is divided into groups and a random sample of groups is drawn.
The correct answer is 12
Set up a ratio and then solve. See paper attached. (:
(1+r)^5=137.76/100
1+r=(137.76/100)^(1/5)
R=(137.76/100)^(1/5))-1
The magnitude of YZ is 8.6
<u>Explanation:</u>
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Y( -4, 12)
Z ( 1, 19)
Magnitude of YZ = ?
We know:

On substituting the value we get:

Thus, the magnitude of YZ is 8.6