Converting Normal Distribution to Standard Normal

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SUMMARY

The discussion focuses on determining the coefficients a and b for the linear combination L=aX1+4X2+bX3, where X1, X2, and X3 are samples from a normal distribution with mean μ≠0 and variance σ²=1/24, to achieve a standard normal distribution. The standard deviation is calculated as σ=1/√24. The user attempts to equate L to the standard normal transformation Z=(X-μ)/σ but expresses uncertainty about the values of a and b, suggesting they may both equal 4, which is incorrect. The correct approach involves calculating the mean and variance of L in terms of a and b.

PREREQUISITES
  • Understanding of normal distribution and standard normal transformation
  • Knowledge of variance and mean calculations for linear combinations of random variables
  • Familiarity with statistical notation and concepts
  • Basic algebraic manipulation skills
NEXT STEPS
  • Learn about the properties of linear combinations of random variables
  • Study the derivation of mean and variance for a linear combination of independent normal variables
  • Explore the Central Limit Theorem and its implications for normal distributions
  • Review examples of converting normal distributions to standard normal distributions
USEFUL FOR

Students studying statistics, particularly those focusing on probability theory and normal distributions, as well as educators seeking to clarify concepts related to standardization in statistics.

Samwise_geegee
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Homework Statement



Let X1,X2,X3 be a random sample from a normal distribution with mean μ≠0 and variance σ2=1/24. What are the values of a and b, respectively, in order for L=aX1+4X2+bX3 to have standard normal distribution?

Homework Equations



σ=1/√24

Converting normal distribution to Standard Z=(X-μ)/σ

The Attempt at a Solution



I tried to set this up by calculating Z for each value of X and setting it equal to L

aX1+4X2+bX3= (X1-μ)/(1/√24) + (X2-μ)/(1/√24) + (X3-μ)/(1/√24)

But doesn't this just mean that a=b=4? I don't really know how to tackle this problem. Any help is appreciated!
 
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Samwise_geegee said:

Homework Statement



Let X1,X2,X3 be a random sample from a normal distribution with mean μ≠0 and variance σ2=1/24. What are the values of a and b, respectively, in order for L=aX1+4X2+bX3 to have standard normal distribution?


Homework Equations



σ=1/√24

Converting normal distribution to Standard Z=(X-μ)/σ




The Attempt at a Solution



I tried to set this up by calculating Z for each value of X and setting it equal to L

aX1+4X2+bX3= (X1-μ)/(1/√24) + (X2-μ)/(1/√24) + (X3-μ)/(1/√24)

But doesn't this just mean that a=b=4? I don't really know how to tackle this problem. Any help is appreciated!

What are the mean and variance of L, in terms of 'a' and 'b'?
 

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