Which of the following is a measure of central tendency?

Appeared in: KPSC Staff Nurse - 2021

Explanation

Measures of central tendency are statistics that describe the center of a distribution of data.
The three main measures of central tendency are the mean, median, and mode.
The median is the value separating the higher half from the lower half of a data sample. To find the median, the data must be arranged in order from least to greatest.
It is the middle number in a sorted list of numbers and is considered a robust measure of central tendency as it is less affected by outliers and skewed data than the mean.

Option A: Range is a measure of dispersion or variability, not central tendency. It represents the difference between the maximum and minimum values in a dataset.
Option C: Standard deviation is a measure of dispersion. It quantifies the amount of variation or spread of a set of data values from the mean.
Option D: Quartile deviation, or semi-interquartile range, is a measure of dispersion. It describes the spread of the middle 50% of the data.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Measures of Central Tendency as background academic context rather than a clinical decision trigger.
Understanding basic biostatistics is crucial for nurses to interpret clinical data, evaluate patient outcomes, and comprehend research findings.
For example, when analyzing the length of hospital stays for a group of patients, the median stay might give a more accurate picture than the mean if a few patients have exceptionally long stays (outliers).
What if? If a dataset of patient blood pressure readings is normally distributed (a symmetrical bell curve), the mean, median, and mode will be very close or identical. In this case, the mean is often the preferred measure of central tendency.

How to Approach the Question

First, identify the key concept in the question stem, which is 'measure of central tendency'.
Recall the definition of central tendency: a single value that describes the center of a data set.
Remember the three main examples of central tendency: mean, median, and mode.
Evaluate each option to see if it fits this definition.
Recognize that 'Range', 'Standard deviation', and 'Quartile deviation' all describe the spread or variability of data, which is known as dispersion, not central tendency.
Conclude that 'Median' is the only option that is a measure of central tendency.

Concept Tested & Keywords

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E6 NursingResearch Sukhpal Kaur pp. 440-442, 464-466

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