Wednesday's responses

1) Yes, the true value for density (of aluminum, 2.70 g/mL) did fall within the 95% confidence interval found by our group: 2.54 g/mL to 3.04 g/mL.
2) The confidence interval becomes wider (increases) as the confidence level increases from 90% (2.62 to 2.96 for our group's results) to 95% to 99% (2.21 to 3.37 g/mL). As I understand the meaning of "confidence level", it is the percent of times that an experiment done just the way we've done it that will come up with the true value within the range of the confidence interval. Given a wider range around the experimental result, we can be more sure that the true answer will fall within that range. If you understand the term this way, than a higher confidence level corresponding to a wider range (increased confidence interval) is intuitive. I mostly deal with 7th and 8th graders lately, and I think that the concepts of confidence interval and confidence level are too heavy and abstract for most of them.
3) If a human error were made in measurement in an experiment like the liquid density portion of the density lab, I can imagine it having affects in either of two directions. If the other measurements averaged a little high (due to errors) and the error in question resulted in a low measurement, then the overall affect of the error in question would be to bring the average closer to the true value. If the other measurements were a little high, and the error in question also caused a high data point, this error would bring the average result farther from the true value.
4) I don't understand the first part of this question - it reads to me like yesterday's question.
Determination of the power output of the bulb in the light lab:
The k value found by our group was 4.7345, but we had used cm in our original distance values. We divided 4.7345 by 10,000 to correct for that.
10^0.00047345*4*pi = 12.58 Watts
5) I have already used Excel in teaching junior high math and will use it more this coming year, in 8th grade Math, and in 8th grade Computers, and I'm thinking about how to use it in 8th grade Science (with radioactive decay, I think). I don't have probes to work with and I have a very small classroom budget, so probes are not in consideration by me. I haven't had much luck in using Google Docs this week, so I have a pretty negative attitude toward that tech tool. Blogging is something that I'll need to give more thought to - I've never had students submit an assignment electronically, but I should because this is a kind of technology tool is a part of their world that they need to be able to work in. Finally, lab quests, I don't know what this tool is.