Normality means data comes from a Gaussian distribution. Data isn't always normally distributed, but can be transformed. Q-Q plot provides graphical visualization of normality
Percentile is a score below which a given percentage of scores falls. Percentiles are expressed in same unit as input scores. No standard definition exists, but similar results for large samples. 25th percentile (Q1), 50th percentile (Q2), 75th percentile (Q3) are common quartiles
Probit is the quantile function associated with standard normal distribution. Defined as inverse of standard normal distribution's cumulative distribution function. Standard normal distribution places 95% of probability between -1.96 and 1.96
SciPy's norm class implements normal distribution with mean and standard deviation. Emperor penguin height example demonstrates normal distribution with mean 40 inches
IQ measures reasoning ability through standardized tests. Most people fall between 60-140, with 68% between 85-115. Average IQ is 100, with scores above 130 considered high
Excel's normal distribution charts help visualize data patterns and make informed decisions. Statistical concepts are transformed into visual representations in Excel. Normal distribution charts are useful in quality control and risk assessment