Lecture Notes Random Variables.docx

Random Variables Activity 1 / Entry Card : list the sample space of the following experiments Experiment 1. Tossing three coins 2. Rolling a die and tossing coin simultaneously

Sample Space

3. Drawing a spade from the deck of cards 4. Getting a defective item when two items are randomly selected from a box of two defective and three non-defective 5. Drawing a card greater than 7 from a deck of cards Activity 2: illustration. Suppose three cell phones are tested at random. Find the sample space Let

N-Non-defective

D- Defective

Sample Space DDD

NNN

DNN

DDN

NND

NDD

DND

NDN

We want to find out the number of defective cell phone that occurs. These are 0, 1,2 or 3. If there is no defective cell Possible Value of phone, we assign 0; if there is 1 defective cell phone we assign number 1; if there are two Outcome Random defective cell phones, we assign 2 and 3 if there are three defective cell phones. The number of Variable defective cell phone is a random variable. The possible values of this random variable are 0, 1, 2 X and 3 NNN Complete the table left to show the values of random variable NND NDN DNN Activity 3:

NDD DND

1. Suppose three coins are tossed. Let Y. be random variable representing the number of tails that occur. Find the values of the random variable Y.

DDN DDD

2. Two balls are drawn in succession without replacement from the box containing 5 red and 6 blue balls. Let Z be a random variable representing the number of blue balls. Find the values of the random variable Z  Random Variable-is a function that associates a real number to each element in the sample space. It is a variable whose value determine by chance. Application Four coins are tossed, Let Z be a random variable represent the number of heads that occur. Find the value of random variable Z Evaluation: From the box containing 4 red and 3 green, 3 balls are drawn in succession without replacement let G be a random variable representing the number of green ball occurs . find the values of the random variable G