Final answer:
To calculate the variance from a probability distribution using a calculator, follow these steps: find the mean, calculate the deviation from the mean, square the deviations, multiply them by probabilities, and add the products. For example, in a probability distribution with values [1, 2, 3] and probabilities [0.3, 0.4, 0.3], the variance would be 0.6.
Step-by-step explanation:
To calculate the variance from a probability distribution using a calculator, you can follow these steps:
- Find the mean of the distribution.
- Calculate the deviation of each value from the mean.
- Square each deviation.
- Multiply each squared deviation by its corresponding probability.
- Add up the products of squared deviations multiplied by probabilities.
- The result will be the variance.
For example, let's say we have a probability distribution with values [1, 2, 3] and probabilities [0.3, 0.4, 0.3]. The mean can be calculated as (1*0.3 + 2*0.4 + 3*0.3) = 2. The deviations would be [-1, 0, 1]. Squaring the deviations gives [1, 0, 1]. Multiplying each squared deviation by its probability gives [0.3, 0, 0.3]. Adding up the products gives a variance of 0.6.