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

It has a symmetrical, bell-shaped curve.

Mean, median, and mode are all equal.

$68\%$, $95\%$, and $99.7\%$ of data falls within $1$, $2$, and $3$ SDs.

$68\%$ of the data lies within $1$ standard deviation.

The mean is $0$ in the standard normal distribution.

It shows how many standard deviations $X$ is from the mean.

$Z = (X - \mu) / \sigma$.

A variable $X$ with normal distribution parameters $\mu$ and $\sigma^2$.

It represents probabilities of continuous quantities.

Use the inverse CDF (percentile function) for calculations.