The positive square root of mean of the squared deviations of value from the arithmetic mean is known as:

Appeared in: AIIMS Raipur lecturer 2021

Explanation

The question provides the precise mathematical definition of standard deviation.
Standard deviation measures the amount of variation or dispersion of a set of data values.
It is calculated as the square root of the variance.
A low standard deviation indicates that the data points tend to be close to the mean, while a high standard deviation indicates that the data points are spread out over a wider range of values.

Option A: Median is a measure of central tendency, not dispersion. It represents the middle value of a dataset, not the spread of data around the mean.
Option B: Mode is a measure of central tendency, not dispersion. It identifies the most frequently occurring value in a dataset.
Option D: Variance is the mean of the squared deviations from the arithmetic mean, but it is not the square root. The question specifically asks for the 'positive square root' of this value.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Definition of Standard Deviation as background academic context rather than a clinical decision trigger.
In nursing, standard deviation is used to understand the normal range for lab values and vital signs. For example, a patient's blood pressure reading can be compared to the mean and standard deviation for their age group to assess if it's unusually high or low.
It is crucial for interpreting medical research. A study reporting a new drug's effectiveness might use standard deviation to show how consistently the drug works across different patients.
What if? If a set of patient recovery times has a very high standard deviation, it means the recovery process is highly variable. Some patients recover quickly, while others take much longer. This would prompt a nurse to investigate the factors causing this variability (e.g., age, comorbidities, adherence to treatment).

How to Approach the Question

This is a factual recall question testing a definition from statistics.
Break down the question's phrase: 'positive square root' of 'mean of the squared deviations'.
Recognize that 'mean of the squared deviations' is the definition of Variance.
The term 'positive square root' of the variance points directly to the definition of Standard Deviation.
Evaluate the options: Median and Mode are measures of central tendency, not dispersion. Variance is a close distractor but lacks the 'square root' component.

Concept Tested & Keywords

Q46_uOBQseYAoOeWOxUReV

E6 NursingResearch Sukhpal Kaur pp. 459-461, 440-442

E6 Comprehensive Textbook of Community Health Nursing for BSc Nursing Students Part 2 — Subpart B (pp 276-535 of 550) p. 21-23

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