Final answer:
The interquartile range (IQR) is a measure of statistical dispersion, an indication of the variability around the median. You calculate it from a dot plot by finding the upper and lower quartiles (middle values of the upper and lower halves of the data) and by subtracting the lower quartile from the upper quartile.
Step-by-step explanation:
The interquartile range (IQR) is a measure of statistical dispersion, or in simpler terms, it is a measure of how spread out the scores in a data set are around the median.
In order to find out the IQR from a dot plot, you would first need to find the median (middle value) of the data set, the lower quartile (Q1, which is the middle value of the lower half of data), and the upper quartile (Q3, which is the middle value of the upper half of the data).
The IQR is then calculated by subtracting the lower quartile from the upper quartile, or IQR = Q3 - Q1.
For instance, if you have scores on a 6-point scale and the Q1 is 3 and Q3 is 5, then the IQR would be 5 - 3 = 2.
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