[MUSIC] Hello everybody and welcome to the second week of the statistics for international business mooc. This week, we're going to introduce you to data description using statistics and numbers. In week one we have discussed how the information in the data may be presented using graphs. And also discussed the fact that there are many different kinds of graphs that can in principle be used. Examples include bar charts, pie charts and frequency distribution. This week we described and summarized the information in the data in our sample using numerical values or measures. These are also able to summarize information. This is a crucial extension to the analysis of the previous week. While graphs are informative, it is usually crucial for improved understanding of the data in hand to discuss their numerical properties. Policymakers and business leaders are keen to have measures that describe the current state of the economy or their business. A major issue for policymakers, business leaders, researchers, and economists, is whether data in their sample is located near a particular value. So this week, we're going to present how to calculate such numerical measures. These measures are the mean, the median and the mode. They help us, in answering questions relating to the location of the center of the data. Now, apart from these measures known as measures of central tendency, sometimes. We also ask questions that concern the position of a particular data point relative to the entire set of our data. We can answer this kind of question by looking at measures of locations such as the z scores and the percentiles. Now these examine the location or position of value in our data set relative to the mean of the distribution. This discussion makes clear that measures of central tendency on their own, may not be able to provide a full and sufficient description of the data in our sample. Hence, in this lecture we are also going to present measures that concern the very ability or the spread of the data with respect to the mean value. These include the range, the variance, the standard deviation, and finally the coefficient of variation. Thank you very much. [MUSIC]