Mathstudent7
New member
- Joined
- Aug 17, 2020
- Messages
- 14
The formula for the population variance is 
Is this formula valid just for a certain population distribution or for any?
The confusion for me occure when I look at the variance for the exponential distribution:
1/Λ2 (1 divided by lambda squared). I know how to get this using integral calculation:
But I am struck by the difference between the two ways of calculating variance.
Assume the mean (my) for a population with a exponential distribution is 2, i.e lambda is then 0.5 (1/2). If i plug in the values my = 2 in the population variance formula and lambda = 0.5 i the variance formula for exponential distribution. Will they give the same answer?

Is this formula valid just for a certain population distribution or for any?
The confusion for me occure when I look at the variance for the exponential distribution:
1/Λ2 (1 divided by lambda squared). I know how to get this using integral calculation:
Assume the mean (my) for a population with a exponential distribution is 2, i.e lambda is then 0.5 (1/2). If i plug in the values my = 2 in the population variance formula and lambda = 0.5 i the variance formula for exponential distribution. Will they give the same answer?