You may hear the weatherperson say, "There is a 30% chance of rain today." Does this mean that it's likely to rain or not? If 0% means there's no chance of rain, and 100% means it's sure to rain, then 30% means there's a slight chance of rain, but most likely it won't rain. What if there is an 80% chance of rain? Then you'd better take your raincoat with you because it's almost certain to rain.
As you can see, probability can also be expressed as a percent. All you have to do is change the probability fraction into a percent and you have the same probability expressed as a percent likelihood or percent chance.
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Example Rhonda and Julie are playing a board game, and they use a die to determine how many moves to make. If Rhonda gets a 4, 5, or 6 on her next throw of the die, she will win the game. What is the chance that she will get a 4, 5, or 6 on her next throw? Step 1: Determine the probability and create a fraction. A die has the numbers 1 through 6 on it, so there are 6 total possibilities. There is one 4, one 5, and one 6 on the die, so there are 3 possibilities out of 6 she will roll a 4, 5, or 6.
\(\mathsf{ P(4, 5, 6) = \frac{\text{Favorable Outcomes}}{\text{Total Outcomes}} = \frac{3}{6} = \frac{1}{2} }\) Step 2: Change the fraction into a decimal. Remember that we can change a fraction to a decimal by dividing the numerator of a fraction by the denominator. So we change \(\mathsf{ \frac{1}{2} }\) to a decimal by dividing 3 by 6. 3 ÷ 6 = .5 Step 3: Change the decimal to a percent. As you remember, we do this by moving the decimal point two places to the right and adding the percent sign. .5 = 50% |
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Question
What is the percent chance of a coin landing on heads?
