Lesson 2

• Probability is the study of random events.
• Probability distribution is a statistical function that describes all the possible values and likelihoods that a random variable can take within a given range.
• P(X) is always equal to one in a discrete probability distribution.
• Probability Histogram displays the probability of each possible value of random variable.
• Mean is also calles as expected value.
• Mean is a weighted average of the possible values that the random variable can take.
• Variance is a measure of variability. It is the difference between the actual value and the expected value.
• Standard deviation or standard error is a measure of dispersant in statistics.