ENGR 100 Lecture Notes - Lecture 29: Histogram, Skewness, Unimodality
Document Summary
Type of graph used to display distributions. Example: occurrences of grades (out of 20) on past tests. When bin size is too narrow, false detail is displayed. When it is too wide, detail is lost. For bell-shaped distributions, h=3. 5s n^(-1/3); where h-bin size, s- standard deviation, n-number of measurements. Common central value measures are mean, median and mode. Median is the middle value when data ordered. If xm is the median value, half of the remaining observation are less than xm and half are greater. If even number of observations, median is the average of the two middle values. E. g. family has five children aged 8, 9, 12, 13, 19. The median age of the children is 12. Suppose only the 4 youngest live at home. The median age of the children living at home is 10. 5 (average of 9 and 12) Value that is observed with greatest frequency relative to its neighbours, or.
