1 Excel Calculation Based on Exercise 21 page 107

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3 Here I am going to explain some Microsoft Excel functions in the context of the example. NOTE: there are many ways to do things in Excel. I mention some below. If you find better ways – go at it! Notice the data set is an the Excel data disk that came with the book. Put the disk in the cd drive and open Excel. Go to file, open. Double click on data files and then chapter 3 and find the crime file. Double click on it. Because I wanted the first column for labels for the information we want, I moved the data over. I did this by clicking on the A column heading. Then I went to insert, column on the main menu. Then I went into the first column and typed what you see. I actually made the first column wider – do you know how to make a column wider? Point at the crease between two columns, click and drag!

4 In Excel you would note the Winter variable and its values are now in cells b1 to b11, denoted in Excel as b1:b11. To get the Range I used the function wizard. I show you the location of this on the next screen. But I first clicked on cell b13. Then hit the function wizard button and go to the statistical functions. The function wizard puts an = sign in the cell. Then scroll to the max function, hit ok and then in the number 1 block put in the array b1:b11. But we are not done because we want to subtract off the minimum value. Go up to the equation window where you see = Max(B1:B11) and hit the minus sign (hyphen) and then hit the function wizard again and find the min function and do as before. Since we want to do the same for the Summer variable, we can copy what we did. Click on cell b13 again and put the mouse on the bottom right of the cell. When you see the little plus sign, click and drag. Then click on cell c13 and look at the window.

5 This is the function wizard button. If you do not see this go to insert and scroll to function.

6 For the first quartile I just used the 25 th percentile function and did the 75 th percentile for the 3 rd quartile. You could use the quartile function. The IQR had to be calculated as =B15-B14. The variance is the var function. The standard deviation is the stdev function. The mean is the average function. The coefficient of variation had to be calculated as =(B18/B19)*100.

7 Now, let’s compare the variability between the two time periods. The Summer has larger values for range, IQR, standard deviation and variance. This would suggest the data for Summer has more variability. Since the two time periods do not have the same means and standard deviations the coefficient of variation was calculated. The calculations add support to the idea that the Summer has more variability of daily crime reports. Assignment # 4 – use data in exercise 20 page 107 but answer the questions parts in exercise 21 (except instead of each period you will look at each company days for delivery). Sorry you have to type in the data. Type it in columns. Use Excel. Type part d in the Excel file toward the bottom. Turn in the Excel printout similar to what I have on slide 2 here.