RESEARCH METHODOLOGY

Detailed explanation-1: -Standard deviation may be abbreviated SD, and is most commonly represented in mathematical texts and equations by the lower case Greek letter (sigma), for the population standard deviation, or the Latin letter s, for the sample standard deviation.

Detailed explanation-2: -A standard deviation is a measure of how unusual a set of data is if a hypothesis is true. Physicists express standard deviations in units called sigma, . The higher the number of sigma, the more incompatible the data are with the hypothesis.

Detailed explanation-3: -s (the greek lower-case letter, “sigma") is usually used for the population standard deviation. s is used to denote the standard deviation of a sample of scores.