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Questions › UoH › UoH 2014 › Q57
1 mark, −0.33Statistics › Random variables and standard distributions › Expectation and varianceModerateabout 1 min

UoH 2014 Question 57: Random variables and standard distributions

Let X and Z be random variables such that X=5Z−20X = 5Z - 20X=5Z−20. Given that mean of X is μX=80\mu_X = 80μX​=80 and its standard deviation is σX=55\sigma_X = 55σX​=55, then,

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Let X and Z be random variables such that X = 5Z - 20. Given that mean of X is μ_X = 80 and its standard deviation is σ_X = 55, then, (A) μ_Z = 80 and σ_Z = 55 (B) μ_Z = 20 and σ_Z = 11 (C) μ_Z = 80 and σ_Z = 11 (D) μ_Z = 20 and σ_Z = 55

Also written as: Let X and Z be random variables such that X = 5Z - 20. Given that mean of X is mu_X = 80 and its standard deviation is sigma_X = 55, then,

Random variables and standard distributions has come up 173 times in 7 exams since 2005.

What this question tests

This question is on Expectation and variance, part of Random variables and standard distributions in Statistics.

The mean and spread of a random variable, and how they change under transformations and sums.

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Question from the UoH 2014 paper. Solutions are TestStop's own. Not affiliated with or endorsed by any examination authority.