What among the following applies to the ‘Ratio scale’?

A. It is a useful device in assessing quality and values
B. It has equal interval properties
C. It has a true zero
D. The numerals have the qualities of real numbers and can be added, subtracted etc.
E. It uses non-parametric statistical techniques

Choose the correct answer from the options given below:

Correct option is D

A Ratio scale is a type of measurement scale that has a true zero, and the ratios of the numbers on the scale are meaningful. It is used to measure continuous variables where both the difference between values and the ratios are significant. 

1. B. It has equal interval properties:

   • True. A ratio scale has equal intervals between each value, meaning the difference between any two consecutive values is the same.

2. C. It has a true zero:

   • True. A true zero means that zero on the scale indicates the absence of the quantity being measured, and you can perform meaningful ratio comparisons. For example, in measuring length, zero means no length.

3. D. The numerals have the qualities of real numbers and can be added, subtracted etc.:

   • True. A ratio scale has the same properties as real numbers, allowing mathematical operations like addition, subtraction, multiplication, and division to be meaningfully performed on the data.

1. A Ratio scale is the highest level of measurement in statistics, and it is characterized by the presence of a true zero point.
2. It is useful for measuring quantities like height, weight, distance, time, and other continuous data.
3. In a Ratio scale, you can make meaningful statements like "twice as large" or "half as much", which are not possible with lower scales like ordinal or nominal.
4. Mathematical operations like multiplication and division are possible due to the meaningful zero point and consistent intervals between values.

• A. It is a useful device in assessing quality and values:
  • Incorrect. While ratio scales are very useful in quantifying quantities, they are typically not used for assessing quality or abstract values (which are usually measured on ordinal or nominal scales).
• E. It uses non-parametric statistical techniques:
  • Incorrect. Ratio scales are parametric in nature and allow for the use of parametric statistical techniques (like mean, standard deviation, correlation, etc.) since they have equal intervals and a true zero.