In: Statistics and Probability
Income (in 1960 dollars/person) for European countries and the
percent of the labor force (in %) that works in agriculture in 1960
are in the table below ('OECD economic development,' 2013). Test at
the 8% level for a negative correlation between percent of labor in
agriculture and income of European countries.
percent of labor in agriculture | income |
---|---|
15 | 1035 |
36 | 529 |
42 | 290 |
44 | 238 |
11 | 1361 |
11 | 810 |
25 | 839 |
20 | 977 |
27 | 504 |
20 | 1013 |
18 | 1049 |
56 | 324 |
23 | 681 |
79 | 177 |
4 | 1105 |
What is H0:
What is HA:
Test statistic, t=
t=r√(1−(r)2(n−2))t=r(1-(r)2(n-2)) =
Make a decision
State a conclusion
Sample correlation coefficient :
x: percent of labor in agriculture | y:income | xy | x2 | y2 |
15 | 1035 | 15525 | 225 | 1071225 |
36 | 529 | 19044 | 1296 | 279841 |
42 | 290 | 12180 | 1764 | 84100 |
44 | 238 | 10472 | 1936 | 56644 |
11 | 1361 | 14971 | 121 | 1852321 |
11 | 810 | 8910 | 121 | 656100 |
25 | 839 | 20975 | 625 | 703921 |
20 | 977 | 19540 | 400 | 954529 |
27 | 504 | 13608 | 729 | 254016 |
20 | 1013 | 20260 | 400 | 1026169 |
18 | 1049 | 18882 | 324 | 1100401 |
56 | 324 | 18144 | 3136 | 104976 |
23 | 681 | 15663 | 529 | 463761 |
79 | 177 | 13983 | 6241 | 31329 |
4 | 1105 | 4420 | 16 | 1221025 |
=431 | =10932 | =226577 | =17863 | =9860358 |
Sample correlation coefficient : r=-0.8595
Null hypothesis : Ho : There is no Correlation Coefficient : = 0
Alternate Hypothesis : Ha : There is negative correlation : < 0
Left tailed test
Test Statistic : t
Degrees of freedom = n-2 = 15-2=13
For 13 degrees of freedom , P(t<-6.0629) = 0.0000
Level of significance :8% : 0.08
As p-value:0.0000 less than level of significance (0.08) reject the null hypothesis.
There is sufficient evidence to conclude that there is negative correlation between percent of labor in agriculture and income of European countries.