Matilda was curious if sample interquartile range (IQR) was an unbiased estimator of population IQR. She placed ping pong balls numbered from 000 to 323232 in a drum and mixed them well. Note that the IQR of the population is 161616. She then took a random sample of 555 balls and calculated the IQR of the sample. She replaced the balls and repeated this process for a total of 505050 trials. Her results are summarized in the dotplot below, where each dot represents the sample IQR from a sample of 555 balls.