IMM250H1 Lecture Notes - Lecture 3: Standard Score, Standard Deviation, Normal Distribution
Document Summary
The normal distribution is a theoretical model with several special features. Unimodal there"s only one clear modal pattern in the data, sometimes they have a lot of modes. Unskewed: mode, median, and mean are same value this is true because of the above. This will be an important concept for the rest of the course because it allows us to make decisions related to hypotheses we test. Area that falls under a normal distribution sums to 1, this area can also be thought of as a set of probabilitites. Approximately 68. 26% of the observations fall within 1standard deviation of the mean. Approximately 95. 44% of the observations fall within 2standard deviations of the mean. Approximately 99. 72% of the observations fall within 3 standard deviations of the mean. When a distribution is normal, z scores put any unit of measurement on a standardized scale where the mean is 0 and the standard deviation is 1.
