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Hi!

My science fair project board is due Nov. 4th and I am having difficulty figuring out how to apply my data in calculating the standard deviation.

My data consists of hue (degrees), saturation (%), and brightness (%) for four different colors of dye (red, purple, yellow, orange) on two types of fabrics (wool and silk). I also experimented with how metal salt mordants affect the dye colors so I have the same data set (hue, saturation, and brightness) for the same four dyes and same two fabrics using two different mordants (aluminum sulfate and ferrous sulfate). I did three trials for each.

Wool - No Mordant
Red - 3 trials, average
Purple - 3 trials, average
Yellow - 3 trials, average
Orange - 3 trials, average

Silk - No Mordant
Red - 3 trials, average
Purple - 3 trials, average
Yellow - 3 trials, average
Orange - 3 trials, average

Wool - Aluminum Sulfate
Red - 3 trials, average
Purple - 3 trials, average
Yellow - 3 trials, average
Orange - 3 trials, average

Silk - Aluminum Sulfate
Red - 3 trials, average
Purple - 3 trials, average
Yellow - 3 trials, average
Orange - 3 trials, average

Wool - Ferrous Sulfate
Red - 3 trials, average
Purple - 3 trials, average
Yellow - 3 trials, average
Orange - 3 trials, average

Silk - Ferrous Sulfate
Red - 3 trials, average
Purple - 3 trials, average
Yellow - 3 trials, average
Orange - 3 trials, average

THEN I exposed all my samples above to sunlight for a period of several weeks and measured the hue, saturation, and brightness for all trials listed above to determine colorfastness. So I have the same number of data sets listed above for the exposed samples.

In total, I have 48 averages (dye colors, exposed dye colors). QUESTION: HOW DO I ORGANIZE MY DATA AND CALCULATE THE STANDARD DEVIATION? WILL I HAVE MORE THAN ONE STANDARD DEVIATION?

My board is due Nov. 4, 2015.

Thank you!

Hello. Please only post your question in one forum so that our experts will reply in a single location and can best answer your questions based on what has already been discussed. It sounds like you received a lot of great advice on your post in the Physical Science forum. Please refer to that thread. Thanks for using Science Buddies, and good luck!