statstics
posted by ellas on .
A distribution of weights is symmetric about its median. The lower quartile of the weights is 90 pounds and the median is 120 pounds. Find the interquartile range of the distribution.

If weights are symmetric about the median then is you have 90 lbs at the lower quartile, you should have 150 at the upper quartile.
Subtract the two numbers to get the interquartile range. 
i did't get it even i got the wright answer , how do u calculated upper quartile ?? on hit and trial basis??

The upper quartile is the 75th percentile.

150