Answer:

Introduction:
Measurement of trend is an important aspect in various fields such as economics, finance, statistics, and market research. It helps in understanding the pattern or direction of change in a particular variable over a specific period of time. There are several methods and tools used for measuring trends, but there is one option that is not used in these measurements. Let's discuss it in detail.

The Options:
The question asks us to identify the option that is not used in the measurement of trend. The options include:

1. Moving averages
2. Index numbers
3. Bar charts
4. Interpolation

Explanation:
Moving averages:
Moving averages are extensively used in the measurement of trend. It helps in smoothing out fluctuations in data and provides a clearer picture of the underlying trend. By calculating the average of a specific number of data points over a given period of time, moving averages help in identifying the direction and strength of the trend.

Index numbers:
Index numbers are also widely used in measuring trends. They compare the value of a variable in a specific time period with its value in a base period. This allows for the tracking of changes in the variable over time and the identification of trends. Index numbers are commonly used in economic indicators such as inflation, stock market indices, and consumer price index.

Bar charts:
Bar charts are visual representations of data that display the values of a variable as vertical bars. While bar charts are not directly used for measuring trends, they can still provide insights into the patterns and changes in data over time. By comparing the heights of the bars in different time periods, one can infer the direction of the trend.

Interpolation:
Interpolation is a method used to estimate values between known data points. It is not directly used in the measurement of trend but can be employed to fill in missing data points or to estimate values at specific time intervals. Interpolation helps in creating a smooth trend line by providing estimated values for the missing or incomplete data.

Conclusion:
Among the given options, none of them can be regarded as the one that is not used in the measurement of trend. Moving averages, index numbers, bar charts, and interpolation are all valuable tools and methods used in analyzing and measuring trends. Each option plays a role in understanding the patterns and changes in data over time, and their combined usage leads to a comprehensive trend analysis.