STAT 1000 Lecture Notes - Lecture 4: Electric Light, Random Variable, Standard Deviation
Document Summary
Dicrete random variable: has either a finite number of possibilities or a countable number of values. Continuous variable has an uncountable infinite number of possible values (takes value in interval or continuum). Ex: the liftetime of a lightbulb is continuous although we tend to make it discrete by grouping it into a number of days. Density curves: taking a histogram and making it a continuous bell distribution so you can caluculate the area under the curve. Density curve: always on or above horizontal axis (density >= 0) Area under the curve and above any range of values is the proportion of all observations that fall in that range. Desntiy curve come in any shape imaginable, bell curve, skewed, square, wiggly, etc. The mean of a density curve is the balance point at which the curve would balance if made of solid material.
