GEOG 3MB3 Lecture Notes - Lecture 4: Nth Root, Weighted Arithmetic Mean, Central Tendency
28 May 2018
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September 20, 2016
Central tendency…
- These are all meant to summarize data into a single measurement point
- Average and median would be point estimators
- This is used as a stand in, for large groups of data
Central tendency
- Tries to represent the middle of a set of data
- The mean is used to describe the average
- The arithmetic mean is the only value that will give you the sum of the original
data
- Mean is often the best single number we can use to summarize data
- The sigmaXi means we are summing all the values of the data and then you
divide the sum by the number of observations you have – this will give you the
average
Geometric Mean
- He won’t test you on this, he just wants to make you aware of it
- It is typically used to measure the central tendencies of growth
- Geometric mean involves multiplying the numbers all together and taking the nth
root of the product
- Often used to measure central tendency when there is a large variability in the
data
Weighted Mean
- This is how your grades are decided
- Multiply each value by the weight it carries then sum all your products up and
divide by the sum of the weights
- Weighted mean and normal mean would only be the same if the weights of
things were the same
- Weighted average can be used to calculate the average when there is a degree
of uncertainty
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
These are all meant to summarize data into a single measurement point. Average and median would be point estimators. This is used as a stand in, for large groups of data. Tries to represent the middle of a set of data. The mean is used to describe the average. The arithmetic mean is the only value that will give you the sum of the original data. Mean is often the best single number we can use to summarize data. The sigmaxi means we are summing all the values of the data and then you divide the sum by the number of observations you have this will give you the average. He won"t test you on this, he just wants to make you aware of it. It is typically used to measure the central tendencies of growth. Geometric mean involves multiplying the numbers all together and taking the nth root of the product.
