A discrete random variable X has a probability distribution with mean ΞΌ = 3.2 and E(XΒ²) = 11.8. Explain what the variance of X measures in the context of this distribution, and determine its value.
Mathematical Methods Β· Unit 3 Β· Discrete random variables Β· General discrete random variables
Determine and use the variance of a discrete random variable as a measure of spread, πππ (π) = β ππ (π₯π β π)2 where ππ is the probability of outcome π₯π occurring, π is the mean.
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Consider the Bernoulli distribution where the outcomes for rolling a standard die are obtaining a five and not obtaining a five. Determine the variance of the resulting Bernoulli distribution in this scenario.
A discrete random variable $X$ represents the number of faulty items in a sample of 5 products from a manufacturing line. The probability distribution is given in the table below. Determine the variance of $X$, correct to 2 decimal places.
A discrete random variable $X$ represents the number of defective items in a batch of 5 items. The probability distribution is given in the table below. Determine the variance of $X$, giving your answer correct to 2 decimal places.