If there are not any lines extending out from the box or there is not a line drawn for the mean, it is possible that the value for the 25th or 75th percentile line is also the largest value within the acceptable range. The mean can also be equal to the 25th or 75th percentile. It is all dependent on the original data.
KaleidaGraph is a thoughtfully designed graphing and data analysis application for research scientists, as well as for those in business and engineering fields. It produces publication-quality graphs, and easily converts the most complex data into a functional display.