Date: Feb 15, 2013 9:14 AM
Author: Luis A. Afonso
Subject: Re: Intra-permutations to test two different mean values

___Hsu solution (same data)

____C.I. 5% significance
____female spiderĀ“s length (mm)= 8.127, male= 5.917, difference = 2.210
____sample variances = 1.285, 0.440
____ sizes = 30, 30
S= sqrt (varfemale/30, varmale/30) = 0.240
_____
Hsu solution: [difference ? T(30df)* S, difference + T(30df)* S]
= [2.210 - 2.0423*0.240, 2.210 + 2.0423*0.240] = [1.720, 2.700]
Which accounts pretty well with the permutationĀ“s results:
[1.76, 2.67]
No surprise because samples are of same size in spite of large variance ratio female/male: 0.34.
Ranges female 10.00- 5.90= 4.10, male 7.50- 4.70= 2.80
Luis A. Afonso