Hi friends! Today will discuss about the Histogram. It is one of the 7 QC tools. A histogram is a visual representation of data that helps us understand the distribution and patterns within a set of values. It’s like a bar chart, but with a specific purpose – showing the frequency of different ranges or groups in your data.
What is a Histogram?
Imagine you have a bunch of numbers, like the scores of students in a class or the heights of students in a class. A histogram organizes these numbers into “buckets” or ranges and shows how many falls into each bucket.
Type of Data – Continuous data.
Why use Histogram?
Spot Patterns: Histograms make it easy to see patterns or trends in your data. Are most scores clustered around a certain range? Are they spread out evenly?
Identify Outliers: Outliers are extreme values that can skew your understanding of the data. Histograms help you spot these outliers.
Distribution Insights: Is the data symmetrical, or does it skew to one side? Histograms provide insights into the distribution of your data.
Let’s understand this with an example. We can use Excel for this. The ages of people in a society are provided below. To input these values into an Excel sheet, select the cell, then navigate to the ‘Insert’ tab and choose ‘Insert Statistical Chart’ as shown in the picture below.
The above picture indicates the distribution of ages in your sample of 35 people.
Age Group (34-50):
- Frequency: 6 people
- This means that 6 individuals in your sample have ages between 34 and 50 years old.
Age Group (50-66):
- Frequency: 11 people
- There are 11 people in your sample whose ages fall within the range of 50 to 66 years old.
Age Group (66-82):
- Frequency: 12 people
- The highest frequency is in this age group, with 12 individuals having ages between 66 and 82 years.
Age Group (82-98):
- Frequency: 6 people
- This indicates that 6 individuals in your sample are aged between 82 and 98 years.
Interpretation:
- The histogram shows a distribution with a peak in the age range of 66 to 82, suggesting that this age group is the most common in the sample.
- The distribution is somewhat right-skewed, meaning that there are fewer individuals in the younger age ranges (34-50 and 50-66) compared to the older age ranges (66-82 and 82-98).
- The overall shape of the histogram provides a quick overview of how ages are distributed in the society.
Key Points:
- Understanding the distribution of ages in your sample can offer insights into the demographics of the society.
- The histogram visually represents the frequency of individuals in different age ranges, making it easier to grasp the age distribution pattern.