Working Principle: Stratified Random Sampling
nx = (Nx/N)*n
where:
nx = sample size for stratum x
Nx = population size for stratum x
N = total population size
n = total sample size
Given:
Nx = 100
N = 1000
n = 0.5*(1000) = 500
Required: Probability of Man to be selected
Solution:
nx = (Nx/N)*n
nx = (100/1000)*500 = 50 men
ny = (Nx/N)*n
ny = (100/1000)*500 = 50 women
Probability of Man to be selected = nx/(nx + ny)*100 = 50/(50+50)*100 = 50%
<em>ANSWER: 50%</em>
<span>Form a sequence that has two arithmetic means between -13 and 89. a. -13, 33, 43, 89 c. -13, 21, 55, 89 b. -18, -36, -72, -144 d. -18, -81, -144
Solution:
Since it has to be between -13 and 89, letter d and b are not anymore considered to be the answer.
for a:
33-(-13)=46=d
43-33=10=d the value for this d is different from the two sequence,
89-43=46=d
they have different value for d, thus this is not the answer!
for c:
21-(-13)=34=d
55-21=34=d
89-55=34=d
they have the same value for d, thus the correct answer is </span><span> c. -13, 21, 55, 89</span>
