Standard Normal Distribution (Edexcel A-Level Mathematics): Flashcards

Finds the value corresponding to a given cumulative probability.

Use the formula: $X = \mu + Z\sigma$ with given area, $\mu$, $\sigma$.

Input Area: $0.58$ as it equals $1 - 0.42$.

$P(X \leq c) = 0.62 + P(X \leq 24) = 0.62 + 0.3085$.

Use $IPR = Q3 - Q1$ for the specific percentiles.

Tom is correct; they are equal in a normal distribution.

$z = (X - \mu) / \sigma$, where $X$ is the value of interest.

They indicate the number of standard deviations from the mean.

Use $z = (6 - \mu) / \sigma$ and look up corresponding $z$-value.

Find $z$ for $0.3$, then use $\sigma = (22 - \mu) / z$.