State the formula to find variance of discrete variable. – InterviewSolution

InterviewSolution

1.

State the formula to find variance of discrete variable.

Answer»

The formula to find the variance of discrete variable is as follows :

σ² = V(X) = E(X²) – [E(X)]²
= Σx²p (x) – [Σx ∙ p(x)]²

Discussion

No Comment Found

Related InterviewSolutions

State the relation between the probability of success and failure in Bernoulli trials.
Find the standard deviation of the binomial distribution having n = 8 and probability of failure
The probability of failure in a binomial distribution is 0.6 and the number of trials in it is 5. Find the probability of success.
The binomial distribution has mean 5 and variance \(\frac{10}{7}\). What will be the type of this distribution ?(a) Positively skewed(b) Negatively skewed(c) Symmetric(d) Nothing can be said about the distribution
Define continuous random variable.
Which of the following is the formula of probability of an event of not getting a success in the binomial distribution with parameters n and p?(a) nC0pnq0(b) nC0p0qn(c) nC0pqn(d) nC0pnq
Define discrete random variable.
Which variable of the following will be an illustration of discrete variable ?(a) Height of a student(b) Weight of a student(c) Blood Pressure of a student(d) Birth year of a student
State the formula to find variance of discrete variable.
Mean and variance of a discrete probability distribution are 3 and 7 respectively. What will be E (X2) for this distribution ?(a) 10(b) 4(c) 40(d) 16