Frequency
Distributions

Dr. Ajay Kumar Koli, PhD | SARA Institute of Data Science, India

Do women tend to prefer ❤️ dating men with higher salaries?

😣😣 “the problem with data is that you usually have too much for your mind to make sense of them”

Frequency Distribution


“Frequency distribution can either be a table or a graph that shows each possible score along with the number of times that score occurred in the data.”

Frequency Distribution

  • Frequency: how many times each score occurs.

  • If you add up the frequencies (\(\sum f\)) you get the sample size (\(N\)).

  • We should mention the category even if the freqency is zero.

🤔 How does this help me to understand whether women are attracted to guys with high salaries?


Relative Frequency: How often a response is observed relative to the total number of responses.

Relative Frequency

\[ relative\;frequency = \frac{frequency\;of\;response}{total\;number\;of\;responses}\\ = \frac{f}{N} \]

Relative Frequency of Rating 10

\[ relative\;frequency = \frac{frequency\;of\;rating\;10}{total\;number\;of\;responses}\\ = \frac{2}{20}\\=0.1 \]

10% of women rated a high salary’s importance at 10 out of 10.

🤯 Your Turn

Calculate Relative Frequency for score 4 on High Salary.

Your Turn: Answer

Cumulative Percentage

Graphical Frequency Distributions: Histograms

Graphical Frequency Distributions: Frequency Polygon

Practice

  • Frequency table

  • Relative frequency table

  • Visualizing Relative Frequencies

Grouped Frequency

“a frequency distribution where we group scores together”

Grouped Frequency Distribution

\[ interval\;width = \frac{range\;of\;scores}{number\;of\;intervals} \]

\[ = \frac{highest\;score - lowest\;score}{number\;of\;intervals} \]

Relationship Assessment Score

The RAS score of 20 similar age group women are:


16, 23, 26, 22, 14, 20, 8, 19, 22, 25,
17, 26, 27, 11, 32, 17, 20, 17, 14, 28.

95% of them rated their relationship satisfaction lower than Alisha (32).

References