Statistics Notes for IIT JEE, Download PDF!

By Subrato Banerjee|Updated : November 22nd, 2018

Statistics constitutes 1-2 questions in JEE Main and is among the most consistently asked topic in JEE Main. Preparation of the topic requires thorough revision from the notes because it is quite often that the concepts asked in the exam are repetitive in nature. Download the pdf file of the short notes on Statistics from the link given below.

The measure of central tendencies

There are three measures of central tendencies:

• Mean (The average value of the data)
• Median (The most probable data)
• Mode (The most frequent data)

Measure of Dispersion

Dispersion refers to scattered data. Two of the measures of dispersion are

• Mean deviation
• Standard deviation

Mean Deviation

The mean deviation about any central tendency or a fixed number within the range of data is the ratio of the sum of the absolute values of deviations from that point to the number of observations.

NOTE: Mean deviation from the mean and median are most commonly used.

Step 1: Calculate the central tendency (mean or median) about which we need the mean deviation.

Step 2: Find the absolute values of deviation of each data from the central tendency.

Step 3: Find the mean of the absolute values of deviation of each data from the central tendency.

Mean Deviation from ungrouped data

about the mean

about the median

Mean Deviation from grouped data

about the mean

about the median

Variance and Standard Deviation

For ungrouped data

The Variance about any central tendency or a fixed number within the range of data is the ratio of the sum of the squared value of deviations from that point to the number of observations.

The square root of the variance is the standard deviation.

Variance is denoted by σ2 and the standard deviation is denoted by σ.

Step 1: Calculate the central tendency (mean or median) about which we need the standard deviation.

Step 2: Find the squared values of deviation of each data from the central tendency.

Step 3: Find the mean of the squared values of deviation of each data from the central tendency.

Step 4: Take the square root of the result obtained in step 3.

About the mean

For a discrete frequency distribution

about the mean

For a continuous frequency distribution

about the mean

Coefficient of variance

The coefficient of variance is the measure of the variations for any statistical distribution.

It is defined as

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Farooq AhmedNov 23, 2018

Thanku
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