University:
York University
Course:
MATH 1131 | Introduction to Statistics I
Academic year:

2022
Views:

71

Pages:

2
Author:

Niklas

Title: LECTURE 4 Text Content: For each classification there is a different graphical representation. PIE CHART - NOMINAL VARIABLE Category Freq Abs. Freq Rel. Freq Not seen 332 0.68 Not liked 40 0.08 Liked 117 0.24 When there are a lot of modalities, instead of using the pie chart, which will be difficult to read, we can use either the DOT PLOT or the BAR PLOT. The bar height is the absolute frequency but also be relative frequency in the x-axis we have the modalities reported in the frequency distribution. BAR PLOT and COMPARISONS In this case the frequencies are relative conditional distribution because we are conditioning on the variable of another variable. Absolute frequency: tot. # student SP Conditional only for this group Title: Lecture 4 Text Content: CONTINUOUS - Histogram The x-axis/rectangle base are the intervals reported in the first column of the frequency distribution. The rectangle area = absolute frequency. The rectangle areas are computed as: base * height. How to draw a histogram: wi = bi - bi-1 di = fi / wi We use the density in the y-axis because the intervals are all different width. Example: Educational factors y-axis are the absolute frequencies. In this case we have to use the relative frequencies in the y-axis because the population are different. Exercise Density = Rel. Freq. / Width