2.4.12 Calculate probabilities from a Normal distribution (A-level only)

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Question 69

The random variable $X$ is normally distributed with mean $μ\mu$ and variance $25$ . Given that $P(μ−3k<X<μ+3k)=0.7P(\mu - 3k < X < \mu + 3k) = 0.7$ :

find the value of $k$ .

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The random variable $Y$ is normally distributed with mean $μ\mu$ and standard deviation $σ\sigma$ . Given that $3μ=4σ23\mu = 4\sigma^2$ and $P(Y>54μ)=0.0228P\left(Y > \frac{5}{4}\mu\right) = 0.0228$ : find the value of $μ\mu$ and the value of $σ\sigma$ .

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2.4.12 Calculate probabilities from a Normal distribution (A-level only) Questions

A Level
Maths
2.4.12 Calculate probabilities from a Normal distribution (A-level only)

A Level
Maths OCR (MEI)
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