Yes. Normal (or Gaussian) distribution are parametric distributions and they are defined by two parameters: the mean and the variance (square of standard deviation). Each pair of these parameters gives rise to a different normal distribution. However, they can all be "re-parametrised" to the standard normal distribution using z-transformations. The standard normal distribution has mean 0 and variance 1.
It means independent of the underlying distribution.
A variable is a measure that can take different values. How often it can take these different values defines its distribution. Mode, median and mean are three common measures of central tendency of distributions.
When comparing the spread or variability rather than the location or mean. For example, men's heights and women's heights. You "know" that, on average, men will be taller but you may want to see if the variability within the two sets is the same or different.
Easy. The mean deviation about the mean, for any distribution, MUST be 0.
Only one. A normal, or Gaussian distribution is completely defined by its mean and variance. The standard normal has mean = 0 and variance = 1. There is no other parameter, so no other source of variability.
Yes. Normal (or Gaussian) distribution are parametric distributions and they are defined by two parameters: the mean and the variance (square of standard deviation). Each pair of these parameters gives rise to a different normal distribution. However, they can all be "re-parametrised" to the standard normal distribution using z-transformations. The standard normal distribution has mean 0 and variance 1.
for symmetrical distributions your mean equals the median. that is one of the properties of the symmetrical distribution.
It means independent of the underlying distribution.
No, not all distributions are symmetrical, and not all distributions have a single peak.
A variable is a measure that can take different values. How often it can take these different values defines its distribution. Mode, median and mean are three common measures of central tendency of distributions.
Variability is an indicationof how widely spread or closely clustered the data valuesnare. Range, minimum and maximum values, and clusters in the distribution give some indication of variability.
When comparing the spread or variability rather than the location or mean. For example, men's heights and women's heights. You "know" that, on average, men will be taller but you may want to see if the variability within the two sets is the same or different.
Easy. The mean deviation about the mean, for any distribution, MUST be 0.
The Normal distribution is a probability distribution of the exponential family. It is a symmetric distribution which is defined by just two parameters: its mean and variance (or standard deviation. It is one of the most commonly occurring distributions for continuous variables. Also, under suitable conditions, other distributions can be approximated by the Normal. Unfortunately, these approximations are often used even if the required conditions are not met!
It is a mathematically calculated summary statistic. With discrete distributions it is the arithmetic mean whereas with a continuous distribution it is the value of the random variable (RV) such that it divides the area under the probability distribution curve in half.
The coefficient of variation (CV) is a measure of relative variability, indicating the degree of dispersion of a distribution relative to its mean. A high CV value suggests greater variability, while a low CV value suggests more consistency. It is useful for comparing the variability of different datasets with differing units of measurement.