Lesson Notes By Weeks and Term v4 - SHS 2
PROBABILITY/CHANCE
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PROBABILITY/CHANCE
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Subject: Mathematics
Class: SHS 2
Term: 2nd Term
Week: 20
Grade code: 2.4.2.LI.2
Strand code: 4
Sub-strand code: 2
Content standard code: 2.4.2.CS.1
Indicator code: 2.4.2.LI.2
Theme: MAKING SENSE OF AND USING DATA
Subtheme: PROBABILITY/CHANCE
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Probability is a branch of mathematics that helps us understand and measure uncertainty. In our daily lives in Ghana, we are constantly faced with situations where the outcome is not certain. Will the trotro arrive on time? Will it rain during the Homowo festival? Will my favourite football team, the Black Stars, win their next match? Probability gives us a way to talk about these chances mathematically. Understanding it helps in making smarter decisions in business, agriculture, games, and even personal choices. This lesson focuses on what happens when we consider the probability of two events happening one after the other.
A. What is Probability?
Probability is a measure of how likely an event is to occur. It is expressed as a number between 0 and 1. A probability of 0 means the event is impossible. A probability of 1 means the event is certain. A probability of 0.5 (or 1/2) means the event is equally likely to happen or not happen.
The basic formula for the probability of an event (E) is: ``` P(E) = (Number of Favourable Outcomes) / (Total Number of Possible Outcomes) ```
Example: What is the probability of getting a '6' when you roll a standard six-sided die? Favourable outcome: {6} (There is only one '6') Total possible outcomes: {1, 2, 3, 4, 5, 6} (There are six faces) P(rolling a 6) = 1 / 6 B. Compound Events: Independent vs. Dependent Events