# Statistics and Probability

 Class Mark Class Size Class size = upper limit – lower limit Range Range = (Maximum value) – ( Minimum value) Empirical Formula Mode = 3 Median – 2 Mean
 Mean Mean of Ungrouped Data Mean for n observations x1, x2, x3,...xn Mean for a discrete series Mean of Grouped Data Direct Method Assumed Mean Method Step Deviation Method Median Median of Ungrouped Data:  To find the median of an individual series, arrange the given numbers in ascending or descending order. Median, if the number of observations n is odd Median, if the number of observations n is even Median of Grouped Data Mode Mode of Ungrouped Data It is the most frequently occurring observation Mode of Grouped Data Probability Probability of an Event ·         The Probability of a sure event  is 1. ·         The probability of an impossible event is 0. ·         The sum of the probabilities of all the outcomes of an experiment is 1. ·         For any event A associated to a random experiment, we have: 