How is a trimmed mean different from a mean or median?

How is a trimmed mean different from a mean or median?

Trimmed means are robust estimators of central tendency. To compute a trimmed mean, we remove a predetermined amount of observations on each side of a distribution, and average the remaining observations. Indeed, the median is an extreme trimmed mean, in which all observations are removed except one or two.

What is 5% trimmed mean?

A trimmed mean is an option in descriptive statistics in many computer programs. For example, with a 5% trimmed mean, the lowest 5% and highest 5% of the data are excluded. The mean is calculated from the remaining 90% of data points.

How do you find the 15% trimmed mean?

In the above example, if we wanted 15% trimmed mean, =0.15, n=10, k=n =1.5. Calculations yield k has an integer part 1, and a fractional part 0.5. R=n-2k=10-2*1.5=10-3=7.

How do you find a trimmed mean example?

2 Answers

1. Trimmed mean involves trimming P percent observations from both ends.
2. E.g.: If you are asked to compute a 10% trimmed mean, P=10.
3. Given a bunch of observations, Xi:
4. If np is an integer use k=np and trim k observations at both ends.
5. R = remaining observations = n−2k.
6. Trimmed mean = (1/R)(Xk+1+Xk+2+…

What’s the difference between trimmed mean and normal mean?

Key Takeaways. A trimmed mean is a method of averaging that removes a small designated percentage of the largest and smallest values before calculating the mean. Using a trimmed mean helps eliminate the influence of outliers or data points on the tails that may unfairly affect the traditional mean.

What happens when you trim the mean of a distribution?

Trimmed means. Because we trim the same amount on each side, trimming removes a longer chunk of the distribution on the right side than the left side. As a consequence, the mean of the remaining points is more representative of the location of the bulk of the observations. This can be seen in the following examples.

Why is the 20% trimmed mean closer to the median?

Because of the asymmetry of the distribution, the mean is dragged towards the right side of the distribution, away from the bulk of the observations. The 20% trimmed mean is to the left of the mean, and the median further to the left, closer to the location of most observations.

How is a trimmed mean calculated in arithmetic averaging?

A trimmed mean (similar to an adjusted mean) is a method of averaging that removes a small designated percentage of the largest and smallest values before calculating the mean. After removing the specified outlier observations, the trimmed mean is found using a standard arithmetic averaging formula.