I've compiled all the weights given in this thread so far (as of October 20, 2006 @ 19:00 EST) and have worked out the statistics. Keep in mind that these results are only as accurate as what was posted. First, here's the results of all the numbers given:
Tenors
sample size: 42
minimum: 6.000 lbs / 2.722 kg
average: 7.312 lbs / 3.317 kg
maximum: 8.375 lbs / 3.799 kg
range: 2.375 lbs / 1.077 kg
std dev: 0.417 lbs / 0.189 kg
Altos
sample size: 9
minimum: 4.500 lbs / 2.041 kg
average: 5.257 lbs / 2.384 kg
maximum: 6.000 lbs / 2.722 kg
range: 1.500 lbs / 0.680 kg
std dev: 0.523 lbs / 0.237 kg
Baris
sample size: 3
minimum: 9.000 lbs / 4.082 kg
average: 10.833 lbs / 4.914 kg
maximum: 12.500 lbs / 5.670 kg
range: 3.500 lbs / 1.588 kg
std dev: 1.756 lbs / 0.796 kg
And for simplicities sake...
68% of all the altos weigh between 4.734 and 5.780 lbs (2.147 and 2.622 kg)
68% of all the tenors weigh between 6.896 and 7.729 lbs (3.128 and 3.506 kg)
Obviously the numbers for tenor are going to be more accurate than those for alto because there were almost four times as many tenors weighed. I would take the numbers for bari with a large grain of salt, since there are only 3 of them in the sample and there was a pretty big difference between their weights.
In the process of compiling these numbers I noticed that there was a wide range of accuracy in the weighing methods. In an effort to determine how much this may or may not effect the results, I went through everyone's descriptions of what they used to weigh their horns (if they even mentioned how they weighed them) and assigned a "score" to the weighing method. Using this, I was able to re-run the statistics with some of the least accurately weighed horns excluded. Rather than ask everyone to append their posts with a description of how they weighed them, I simply excluded the ones that were more than likely not very accurate (i.e. guesswork or rounded off more than about 0.2kg / 7 ounces) and gave the benefit of the doubt to those who didn't describe how they weighed the horns. The result of excluding these was minimal (i.e. the average alto and tenor weight changed by about 1%, or 0.06 lbs / 0.0275 kg), in my opinion, and only ended up removing 3 altos and 6 tenors from the samples. Only including the horns that were weighed very accurately reduced the sample size of tenors to only 18, but still only changed the averages by a little over 1%; not so much as to be useful to our discussion at this point.
If anyone is interested in more info about how I calculated this stuff, just ask away (or PM me). If anyone wants the raw data (spreadsheet), PM me and we'll work out how to get you the file.
Enjoy!
-peter