Khan Open Class-Statistical Study Notes: (1) median and statistical charts

I. Median

There are many ways to calculate the median of a heap:

1. Mean, that is, average, returns the mean.

2. Median sorts the number in the median, and finds the data in the middle. If it is an even number, the two numbers in the middle are average.

3. mode and mode. The maximum frequency.

4. Mid-range. Range = MAZ-min, which is the range of the maximum value minus the minimum value and the number distribution. Mid-Rand is (MAX + min)/2, which is the middle value of the range.

This indicates that different methods are used to calculate the median. Different results may be misleading. For example, in terms of average income, there can be a big gap between mean and media.

Ii. Statistical Chart

Describes the applicable scenarios of different statistical charts.

1) pictogram

2) column chart; 3) line chart; 4) pie chart;

5) line chart

Sometimes different scales may lead to the illusion that putting them in the same graph can avoid misleading scale.

6) stem and leaf chart

Stem-leaf: stem indicates different layers, and leaf indicates data in layers. For example, a basketball team score can be divided into dozens of different levels. 0, 1, and 2 in stem indicate the single-digit score of a player. The score is 1x or twenty. Leaf indicates the specific single-digit score.

7) box-and-whisher

These images are rarely used and will not be misled by the mean method. The data range is 4 quarter, and the number of samples for each Q is the same. First, find median, for example, 21 in this figure, and then find median (14) in the first half ), and the last half of Meida (33 ). I think it is only accurate to calculate the average income in this way. It is not based on the principle that the average income is a different value from the actual feeling.

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