Can you have a negative mean value?
The mean of the distribution is the location of the value with the highest likelihood, which could be anywhere. So, yes, the mean can be positive, negative or zero. That does not say, however, that when applying the Normal distribution to the real world that a negative mean makes sense or is often seen.
Why is my mean negative?
It simply means that the values and frequency for the data you are analyzing had enough negative values that the mean was negative. It could simply be that your data had more negatively valued observations than positive.
What does it mean to say a sample is lognormal?
A lognormal (log-normal or Galton) distribution is a probability distribution with a normally distributed logarithm. A random variable is lognormally distributed if its logarithm is normally distributed. Values must be positive as log(x) exists only for positive values of x.
Can a lognormal distribution give negative mean for?
Kindly provide solution as soon as possible.. Join ResearchGate to ask questions, get input, and advance your work. Yes, it is possible to have a negative value for lognormal mean.
How to calculate the density of a lognormal distribution?
The general formula for the probability density function of the lognormal distribution is where σ is the shape parameter (and is the standard deviation of the log of the distribution), θ is the location parameter and m is the scale parameter (and is also the median of the distribution). If x = θ, then f ( x) = 0.
How is the lognormal distribution used in sedimentology?
Also in petrophysics, the lognormal is well-known for pemeability and the semi-logarithmic permeability/porosity plots. In sedimentology in grainsize distribution and bed-thickness distributions. Source rock samples along a borehole usually give a lognormal distribution for the TOC values.
Why is lognormal distribution important for prospect appraisal?
The lognormal is important for prospect appraisal because a variety of the geological factors are so distributed. Also in petrophysics, the lognormal is well-known from the semi-logarithmic permeability/porosity plots. In sedimentology in grainsize distribution and bed-thickness distributions.