What if IQR is negative?

What if IQR is negative?

An interquartile range should be mentioned as 12.5(8.5-10). However, if a negative number is included, it would need to be as -12.5(-8.5- -10).

How do you find the outlier boundaries with IQR?

Here are the steps:

1. Find the IQR.
2. Multiply the IQR by 1.5.
3. Add the resulting number to Q3 to get an upper boundary for outliers.
4. Subtract the same resulting number (from #2) from Q1 to get a lower boundary for outliers.
5. If a number in the data set lies beyond either boundary, it is considered an outlier.

Is the IQR always positive?

Note that the IQR can never be negative, but medians certainly can be negative; it’s not clear that it usually makes sense to compare the two, since one is a location measure and the other is a measure of spread.

How do you calculate inner and outer fences?

These two numbers form our inner fence. For the outer fences, we start with the IQR and multiply this number by 3. We then subtract this number from the first quartile and add it to the third quartile. These two numbers are our outer fences.

Is there a negative number for the inner fence?

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.

What is the interquartile range of inner fences?

The interquartile range IQR = 60 – 50 = 10. Next, we see that 1.5 x IQR = 15. This means that the inner fences are at 50 – 15 = 35 and 60 + 15 = 75. This is 1.5 x IQR less than the first quartile, and more than the third quartile.

How is the IQR used to build a fence?

To build this fence we take 1.5 times the IQR and then subtract this value from Q1 and add this value to Q3. This gives us the minimum and maximum fence posts that we compare each observation to.