# Negative inner fence value in a box and whiskers plot?

I calculated a negative lower inner fence value. I've double checked my work but I can't figure out what's wrong. I was under the impression that these values couldn't be outside of the min and max (duh).

My values range from 0.06188 to 1.90957 and when I plot them in Graphpad it looks fine. I'm plotting with the 10% and 90% percentile whiskers (calculated as 0.515 and 1.359 respectively by Graphpad).

I'm calculating the fraction of my datasets that are outside of the Tukey range (+/- 1.5*IQR), and the 10% and 90% range (possibly outliers). But when I calculate the Tukey fences myself using

lower inner = Q1-1.5(IQR)
upper inner = Q3+1.5(IQR)


I get a negative number for the lower value (-0.06758).

I calculated the 10%/90% using Graphpad, so that's not a problem for now.

Here's are the values, if anyone wants to recreate my calculations.

0.06187564,0.2931995,0.4433044,0.4908953,0.4992562,0.5123487,0.5188922,0.5326462,
0.5400167,0.5722309,0.6232626,0.6340977,0.6361935,0.6417624,0.6618853,0.6727413,
0.6990075,0.7250414,0.7575482,0.8221549,0.8573231,0.8732418,0.8749654,0.8751485,
0.88039,0.8831163,0.8842309,0.8927583,0.9143585,0.9371856,0.9644587,0.9662355,
0.9758021,0.9919777,1.004403,1.027557,1.037168,1.057354,1.075599,1.110754,1.120563,
1.135613,1.135632,1.135986,1.137239,1.148205,1.156857,1.175097,1.197407,1.21761,
1.219516,1.265934,1.304216,1.310815,1.336853,1.341317,1.357579,1.359387,1.462214,
1.552785,1.621189,1.760872,1.909566


It has to be something dumb I'm missing.