Standard error of mean is calles as –
**Core Concept**
The standard error of the mean (SEM) is a statistical measure that estimates the variability of the mean value obtained from a sample of data. It is used to quantify the precision of a sample mean and to compare it with a population mean.
**Why the Correct Answer is Right**
The SEM is calculated by dividing the standard deviation (SD) of the sample by the square root of the sample size (n). This formula is: SEM = SD / √n. The SEM represents the standard deviation of the sampling distribution of the sample mean. It is an essential concept in hypothesis testing and confidence interval construction. When the SEM is small, it indicates that the sample mean is likely to be close to the population mean.
**Why Each Wrong Option is Incorrect**
**Option A:** Not applicable (SEM is a specific statistical measure).
**Option B:** Standard deviation of the mean ( incorrect term, as SEM is the measure of variability of the mean, not the mean itself).
**Option C:** Standard error of the population ( incorrect, as SEM is calculated from a sample, not the entire population).
**Clinical Pearl / High-Yield Fact**
The SEM is a crucial concept in research and clinical trials. It helps to determine the sample size required to detect a statistically significant difference between groups. A small SEM indicates a more precise estimate of the population mean.
**Correct Answer: SEM. Standard error of the mean.**