Aha! Thanks!gleem said:
Standard deviation is a measure of how spread out a set of data is from its mean. It is important because it allows us to understand the variability and distribution of data, which can help us make more accurate conclusions and predictions.
The formula for calculating standard deviation is the square root of the sum of squared differences between each data point and the mean, divided by the total number of data points. This can also be represented as the square root of the variance.
Population standard deviation is calculated using all data points in a population, while sample standard deviation is calculated using a subset of data points from a larger population. Sample standard deviation is used when we want to make inferences about a larger population based on a smaller sample.
The normal distribution curve, also known as the bell curve, is a graphical representation of a data set that follows a symmetrical and bell-shaped pattern. Standard deviation is used to measure the spread of data around the mean on this curve, with 68% of data falling within one standard deviation, 95% falling within two standard deviations, and 99.7% falling within three standard deviations.
No, standard deviation cannot be negative. It is always a positive value because it is calculated by taking the square root of the sum of squared differences, which cannot be negative. A low standard deviation indicates that the data points are close to the mean, while a high standard deviation indicates that the data points are more spread out.