Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Statistics in Excel Things about Excel you absolutely have to know • Autofilling cells – dragging – Home | Fill • Referencing cells – A1, A1:A10, B5 * A1 – absolute referencing … B5 * $A$1 Excel’s statistical capabilities Name box Insert function button Formula bar Formulas | Insert function • Insert function – Shft F3 • Try it: – Autofill values in column, calculate their =SUM • Array functions – calculates multiple values and puts them into an array of cells, e.g. =FREQUENCY (binning) • Give column a name =SUM(Name_of_the_column) Add More Stat into Excel • • File | Options | Add-Ins | Manage | Go… Analysis ToolPak Now, you have Data | Data Analysis Try now Center • =AVERAGE • =AVERAGEA – does not ignore cells with text, if a cell has text, its treated as value 0 – not very useful, anyway • =AVERAGEIF, =AVERAGEIFS – conditional, IFS includes more conditions • =MEDIAN – data does not have to be sorted Deviations • variance – average of the squared deviations 2 X X N 2 s2 X X 2 N 1 – =VARP, =VARPA … population variance – =VAR, =VARA … sample variance • Use =VARP if your data represent the whole population. If you know your data are just a sample from much larger population, use =VAR. • Try yourself: what is the population and sample variance of the following data: 50,47,52,46,45 Standard deviation 2 X X 2 N • =STDEVP, =STDEVPA • =STDEV, =STDEVA s s2 X X N 1 2 Standards • =STANDARDIZE – mean and standard deviation must be calculated aforehead – Try it • =RANK – Simply rank the data in the array – Range in Ref field must have absolute references – Try it • =PERCENTILE – find the value at the given percentile • Data | Data Analysis | Rank and Percentile – Try it CLT simulation • Show, that population that is not normally distributes results in normally distributed sampling distribution. • Use huge population consisting of three variables that can take a value of just 1, 2, 3. Each of this variable is equally likely to appear. – What is the name of such distribution? • Select a cell D2, use =RANDBETWEEN(1;3) • Autofill the two cells right to the D2 • In G3, calculate average of D2:F2 =AVERAGE(D2:F2) • Autofill remaining rows, so you have at least 100 rows • Enter possible values of the sample mean into column I – Express the possible values as fraction – Before doing this, you must change the format of I column to Fraction • Select J3:J9, Formulas | More Func | Statistical | FREQUENCY – Data_array – data in G col – Bin_array – I col – Close the dialog box by Ctrl-Shft-Enter • Insert | Columns – Choose the first layout in the 2D graph