Download QMS 102/204

QMS 102/204 Binomial/Poisson Calculator Tricks 9 The Casio calculator does not compute questions that contain a greater than or greater than equal 9 It does compute “less than and equal” to 9 Therefore, when given a question dealing with greater than, you must convert it into a less than equal to sign The following examples elaborate on the above: Question Notation Conversion for Calculator X: Statement Calculator Greater than P(x > 3) 1 – P(x < 3) 3 Greater than equal to P(x > 3) 1 – P(x < 2) 2 Less than P(x < 3) P(x < 2) 2 Less than equal to P(x < 3) None 3 Central Limit Theorem 9 These types of questions may look like a question involving normal distribution. In fact it is a normal distribution; however you must first convert the standard deviation of the population into the standard deviation of the sample. 9 The trick is that a question will give you sample data that is expressed on a per unit basis and then ask for the entire sum 9 Example: the weight of mini‐boxes of raisins has a mean of 14.1 grams and a standard deviation of 1.4 grams. What is the probability that a case of 50 boxes will weigh more than 725 grams? 9 In the above example 14.1 grams it the weight of ONE mini‐box! Whereas the question is asking what is the probability weight for 50 boxes beyond 725 grams? 9 Please refer to the textbook for the notation (formula) 9 The above illustrates that the mean of the population is equal to the mean of the sample. However the standard deviation of the population is NOT equal to the sample deviation, therefore you must use the formula General Tips and Tricks (READ CAREFULLY) 9 Understand your professor; know what he/she requires of you. For instance, some have preferences for rounding rules or other rules that contradict the textbook. Understanding your professor will allow you to maximize your marks. 9 Know how to use the calculator, if you have any questions consult the book or your professor or drop into the student resource centre 9 Remember to use templates outlined in the textbook for binomial, normal, inverse normal etc. as these are worth substantial marks on any examination! 9 Questions involving space or time would normally be treated as a Poisson question 9 Some students get confused on weighted mean questions. Remember to read the required before entering numbers on your calculator. An example is as follows. Example Demand Probability 8 .3 9 .3 10 .1 11 .3 For each level of demand, the revenue is $10 and the cost is $4. Calculate overall expected profit. In the above example, some students will enter demand in list one and the probabilities in list 2. This is incorrect, the question is asking you expected profit, therefore your list 1 should be the profit for each level of demand. Simply multiply the profit (10‐4) = 6 by each level of demand to get your list 1. ********Remember to change your xlist and frequency distributions settings on your calculators accordingly******** Formula Review Co‐efficient of Variation (CV) = S / Mean of the Sample (Refer to text) 9 Usually you are given with two sets of data and ask to calculate the relative variability. If the question asks for the lowest variability then simply choose the lowest one.