# Question: There is no consistent way of defining an outlier that

There is no consistent way of defining an outlier that everyone agrees upon. For example, some people refer to an outlier that is any observation more than three standard deviations from the mean. Other people use the box plot definition, where an outlier (moderate or extreme) is any observation more than 1.5 IQR from the edges of the box, and some people care only about the extreme box plot type outliers, those that are 3.0 IQR from the edges of the box. The file S02_18.xlsx contains daily percentage changes in the S&P 500 index over a four-year period.

Identify outliers—days when the percentage change was unusually large in either a negative or positive direction—according to each of these three definitions. Which definition produces the most outliers?

Identify outliers—days when the percentage change was unusually large in either a negative or positive direction—according to each of these three definitions. Which definition produces the most outliers?

## Answer to relevant Questions

Sometimes it is possible that missing data are predictive in the sense that rows with missing data are somehow different from rows without missing data. Check this with the file S02_32.xlsx, which contains blood pressures ...The file S02_35.xlsx contains (fictional) data from a survey of 500 randomly selected households. Use Excel filters to answer the following questions. a. Identify households that own their home and have a monthly home ...The file S02_46.xlsx lists the fraction of U.S. men and women of various heights and weights. Use these data to estimate the mean and standard deviation of the height of American men and women. Do the same for weights.The file S02_55.xlsx contains monthly sales (in millions of dollars) of beer, wine, and liquor. The data have not been seasonally adjusted, so there might be seasonal patterns that can be discovered. For any month in any ...In the smoking/drinking example in this section, we used the function COUNTIFS function (new to Excel 2007) to find the counts of the joint categories. Without using this function (or pivot tables), devise another way to get ...Post your question