I am not quite sure what you are asking. If this answer is not complete, please be more specific.
There are many probability density functions (pdf) of continuous variables, including the Normal, exponential, gamma, beta, log normal and Pareto.
There are many links on the internet. I felt that the related link gives a very "common sense" approach to understanding pdf's and their relationship to probability of events.
As explained in the video, a probability can be read directly from a discrete distribution (called a probability mass function) but in the case of a continuous variable, it is the area under the curve that represents probability.
The integral of the density function from the given point upwards.
The formula, if any, depends on the probability distribution function for the variable. In the case of a discrete variable, X, this defines the probability that X = x. For a continuous variable, the probability density function is a continuous function, f(x), such that Pr(a < X < b) is the area under the function f, between a and b (or the definite integral or f, with respect to x, between a and b.
True
Yes. It is a continuous variable. As used in probability theory, it is an example of a continuous random variable.
A discrete random variable (RV) can only take a selected number of values whereas a continuous rv can take infinitely many.
No. The probability that a continuous random variable takes a specific value is always zero.
The integral of the density function from the given point upwards.
You integrate the probability distribution function to get the cumulative distribution function (cdf). Then find the value of the random variable for which cdf = 0.5.
The formula, if any, depends on the probability distribution function for the variable. In the case of a discrete variable, X, this defines the probability that X = x. For a continuous variable, the probability density function is a continuous function, f(x), such that Pr(a < X < b) is the area under the function f, between a and b (or the definite integral or f, with respect to x, between a and b.
It is a discrete random variable.
True
Yes. It is a continuous variable. As used in probability theory, it is an example of a continuous random variable.
A probability density function can be plotted for a single random variable.
A random variable is a variable that can take different values according to a process, at least part of which is random.For a discrete random variable (RV), a probability distribution is a function that assigns, to each value of the RV, the probability that the RV takes that value.The probability of a continuous RV taking any specificvalue is always 0 and the distribution is a density function such that the probability of the RV taking a value between x and y is the area under the distribution function between x and y.
continuous random variable
A probability density function (pdf) for a continuous random variable (RV), is a function that describes the probability that the RV random variable will fall within a range of values. The probability of the RV falling between two values is the integral of the relevant PDF. The normal or Gaussian distribution is one of the most common distributions in probability theory. Whatever the underlying distribution of a RV, the average of a set of independent observations for that RV will by approximately Gaussian.
Usually we consider a random variable which assigns a value to the outcome of an event. The value assigned to the outcome can be either discrete or continuous. The continuous random variable is a random variable whose domain is defined over a continuous range. Examples: Daily inches of rain, speed of cars on highway, purchases made everyday at grocery stores.