Health Sciences 2801A/B Lecture Notes - Lecture 10: Squared Deviations From The Mean, Statistical Inference, Standard Deviation

• School: Western University
• Department: Health Sciences
• Course: Health Sciences 2801A/B
• Professor: Christopher Lee

Document Summary

Mean: the arithmetic average of the data. Median: the point that divides the data in half. Most common method of describing central tendency. The exact middle score in a data-set. Middle number is always (n + 1)/2. If you have a tie for most repeated score, you will have more than one mode. If the distribution is normal, the mean, median, and mode are all equal. In the majority of our inferential statistics, we"ll use the mean. Standard deviation is calculated across all scores as the square root of the sum of the squared deviations from the mean, divided by the number of scores: computational formula: This tends to be cumbersome in practice, and so we generally compute standard deviation with this computational formula. Most common normal distribution is the standard normal distribution. 68% of all data will fall within 1 standard deviation of mean. 95% of all data will fall within 2 standard deviation of mean.