SaiBook.us Statistics

Example

Title: Multiplication theorem for Independent Events

Grade: 9-a Lesson: S3-L4

Explanation: The best way to understand statistics is by looking at some examples. Take turns and read each example for easy understanding.

Examples:

A die is rolled and a coin is tossed.What is the probability that a 3 is rolled on the die and a head is tossed on the coin?

Step 1a

Assumption of probabilities

Explanation:

Die has following on each of its face ⇒ Sample space(die):{1,2,3,4,5,6}

Event A : Rolling a 3 on the die

⇒ \$P(A) = 1/6\$

Coin has two faces ⇒ Sample space(coin):{H,T}

Event B : Tossing a head with the coin

⇒ \$P(B) = 1/2\$

Step 1b

Finding the probability

Explanation:

P (A ∩ B) = P(A) P(B)

P (A ∩ B) = \$(1/6)(1/2)\$

P (A ∩ B) = \$1/12\$

Probability that a 3 is rolled on the die and a head is tossed on the coin = \$1/12\$