University:
McMaster University
Course:
STATS 1LL3 | Introduction to Probability and Statistics
Academic year:

2023
Views:

258

Pages:

2
Author:

Sabrina S.

Video 6: Summarising information using graph Pie charts are a great way to show composition Bad pie charts → the categories don't add up to 100% units not comparable pie slices do not reflect proportions What kind of data are we dealing with? quantitative (fully numeric) (histogram or scatter plot or box plot) qualitative (categorical or nominal) (pie chart or bar graph) ordinal data (ranked or ordered) (steps aren't necessarily the same size) CH 1: Exploring data We define statistics as the science of decision making in the face of uncertainty. What do we mean by data? data is information Either you get data drips (too little info) or data floods (too much data) different types of data (qualitative and quantitative) non-numerical always numerical (nominal) Video 7: Summary measures of location and spread Summary Statistics: numerical (rather than graphical) summaries of data. A Statistic is any quantity calculated from the data values of a sample Standard deviation on excel Step by Step find mean of data get (-AVERAGE(())) in new column, find Xi - X (x - mean) for each Xi take value in step 2 and square it in new column, (x - mean)^2 find the sum of all Standard deviations (step 3) (AUTOSUM) Sum of all stdeviation divided by (sample size - 1) this equals variance Square root to get standard deviation (x - x)^2 OR STDEV.S (all values in data set row) 5 number summary on excel min QUARTILE (range; 0) LQ - QUARTILE (range; 1) QUARTILE (range; 2) median QUARTILE (range; 3) UQ may QUARTILE (range 4) Strays → unusually small or large numbers median ( less less than than = median 6 (median - LQ) 3(median - LQ) outliers) more extreme are outliers Move Mort thon than median + 3 (ua median) median + 6 (UQ-median)