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How to calculate probability of frequency

Calculating the probability of an event happening (in other words, calculating the probability of an event's frequency) isn't as simple as taking a quick look at the event. For example, if you toss a coin once, the odds of tossing a "head" are 1:2. However, the probability of getting three heads in a row isn't the same as getting one head in one flip. Calculating the probability of a simple event involves a little basic probability and a dash of arithmetic.

Instructions

- 1
  Identify the probability of success. For example, the probability of a coin landing with the heads side up is 1:2 (one chance in 2), while the probability of rolling a one using a six-sided die is 1:6.
- 2
  Identify the number of trials. How many times will you flip the coin or roll the die?
- 3
  Multiply the probability of success from Step 1 by itself for each trial from Step 2. For example, if you plan to flip a coin three times in a row, and want to know the probability of the coin landing on heads all three times, you would multiply ½ three times: ½ * ½ * ½ = 1/8, or one chance in eight.

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