How Can the Sum of Independent Normal Random Variables Be Represented?

In summary, the question asks if there is a way to represent the sum of random variables with a normal distribution by using another random variable. The central limit theorem is mentioned, but not applicable due to the lack of a normalizing factor. The distribution function does not converge to a specific value as n approaches infinity.
  • #1
Apteronotus
202
0
For random variables Xk~N(0,1) is there any way of representing the following sum by another random variable?
[tex]
lim_{n\rightarrow \infty}\sum_{k=0}^n X_k
[/tex]

thanks
 
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  • #2
What does the central limit theorem have to say about this question?
 
  • #3
D H said:
What does the central limit theorem have to say about this question?

Thanks DH for your reply, but I've already taken the CLT into consideration. However, since there is no normalizing factor (1/n) in front of the sum I didn't think it applied.

Does it?
 
  • #4
Apteronotus said:
For random variables Xk~N(0,1) is there any way of representing the following sum by another random variable?
[tex]
lim_{n\rightarrow \infty}\sum_{k=0}^n X_k
[/tex]

thanks
The random variable for sum to n is normal with a variance = n. The distribution function does not converge to anything as n -> ∞.
 
  • #5


Yes, there is a way of representing this sum by another random variable. This sum can be represented by a Normal random variable with mean 0 and variance n. This is because the sum of independent Normal random variables with mean 0 and variance 1 is also a Normal random variable with mean 0 and variance equal to the sum of the variances of the individual random variables. As n approaches infinity, the variance of this new Normal random variable also approaches infinity, representing the fact that the sum of an infinite number of Normal random variables becomes increasingly spread out.
 

FAQ: How Can the Sum of Independent Normal Random Variables Be Represented?

What is the "Sum of Normal random numbers"?

The sum of Normal random numbers is a mathematical concept that refers to the total value obtained by adding together a set of random numbers that follow a Normal (or Gaussian) distribution. This distribution is often represented by a bell-shaped curve and is commonly used to model real-world phenomena such as height, weight, and IQ.

How do you calculate the sum of Normal random numbers?

The sum of Normal random numbers can be calculated by simply adding together each individual value in the set. For example, if you have 5 Normal random numbers with values of 2, 4, 6, 8, and 10, the sum would be 30 (2+4+6+8+10=30).

What is the significance of the sum of Normal random numbers?

The sum of Normal random numbers has various applications in statistics, probability, and data analysis. It is often used to determine the overall mean or average of a set of data points, and is also important in calculating standard deviation, which measures the spread of the data.

Can the sum of Normal random numbers be negative?

Yes, the sum of Normal random numbers can be negative if the individual numbers in the set are negative. However, if the numbers are all positive, the sum will also be positive.

What is the relationship between the sum of Normal random numbers and the Central Limit Theorem?

The Central Limit Theorem states that as the sample size increases, the distribution of sample means will approach a Normal distribution. This means that the sum of Normal random numbers will also approach a Normal distribution as the sample size increases, making it a fundamental concept in the Central Limit Theorem.

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