In: Math
Income
Person |
(Yi) |
F(Yi) |
1 | 79.6 | 0.1 |
2 | 138.7 | 0.2 |
3 |
173.1 |
0.3 |
4 |
187.8 |
0.4 |
5 |
201.3 |
0.5 |
6 |
226.6 |
0.6 |
7 |
247.4 |
0.7 |
8 |
289.2 |
0.8 |
9 |
322.8 |
0.9 |
10 |
587.9 |
1 |
A. The mean or average of the ranked above data for a village in Peru is:
a. $245.44
b. $345.44
c. $123.44
d. $200.56
B. Suppose that the covariance between the ranked income and the cumulative distribution of income is 33.24. The Gini coefficient for this village is approximately:
a. .212
b. .223
c. .271
d. .281
solution:
A answer:
mean or average=xi/n
= (79.6+138.7+173.1+187.8+201.3+226.6+247.4+289.2+322.8+587.9)/10
=2454.4/10
mean or average = $245.44
hence,the mean or average of the ranked above data for a village in peru is 245.44
from given options the option' (a)' is correct.
(B) answer:
here we have to find the covariance between Yn and F(YN) fromthe table.
we know that
the formula for covariance is given by
covariance=mean[Yn=mean(F(Yn)]
Mean | 245.44 |
Mean(F(Yn)) | =0.55 |
now to draw the table it shows the covariance was obtained.which is already mentioned in the
questionas33.24
person | income(Y) | F(Y) | F(Yn)-mean(F(Yn)) | F(Yn)-mean(F(Yn)) | Yn-mean(Yn)*F(Yn)-mean(F(Yn)) |
1 | 79.6 | 0.1 | -165.84 | -0.45 | 74.628 |
2 | 138.7 | 0.2 | -106.74 | -0.35 | 37.359 |
3 | 173.1 | 0.3 | -72.34 | -0.25 | 18.085 |
4 | 187.8 | 0.4 | -57.s64 | -0.15 | 8.646 |
5 | 201.3 | 0.5 | -44.14 | -0.05 | -0.942 |
6 | 226.6 | 0.6 | -18.84 | 0.05 | -0.942 |
7 | 247.4 | 0.7 | 1.96 | 0.15 | 0.294 |
8 | 289.2 | 0.8 | 43.76 | 0.25 | 10.94 |
9 | 322.8 | 0.9 | 77.36 | 0.35 | 27.076 |
10 | 587.9 | 1 | 342.46 | 0.45 | 154.107 |
33.24 |
G=2*COV(Yn,F(Yn))/mean
from the formula
G=(2*33.24)/mean(Yn)
G=66.48/245.44
G=0.271
Hence the correct option is 'C'