**6. Incorrect. The
answer is true not false.**

Arrange x and y in the ascending order of magnitude and assign corresponding ranks. Then compute the difference in ranks, d, and the sum of difference in ranks squared.

x |
1 |
3 |
4 |
6 |
8 |
9 |
11 |
14 |

rank of x |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |

y |
1 |
2 |
4 |
4 |
5 |
7 |
8 |
9 |

rank of y |
1 |
2 |
3.5 |
3.5 |
5 |
6 |
7 |
8 |

D |
0 |
0 |
0.5 |
-0.5 |
0 |
0 |
0 |
0 |

d |
0 |
0 |
0.25 |
0.25 |
0 |
0 |
0 |
0 |

Σd^{2}=0.5

r_{rank} = 1- 6Σd^{2}/(n(n^{2}-1))=0.9940
which is slightly higher than the result of problem 6.