Calculate Sums, Rates, and Percentages in Excel: Student Workbook

Transcription

1 2016 Calculate Sums, Rates, and Percentages in Excel: Student Workbook Created by: EVA CONSTANTARAS / Independent Consultant & Data Scientist WITH SUPPORT FROM THE WORLD BANK AND THE UK DEPARTMENT FOR INTERNATIONAL DEVELOPMENT (DFID)

2 Lab 1: Calculating Sums, Rates, and Percentages in Excel 1 Lab 1: Calculate Sums, Rates, and Percentages in Excel STUDENT WORKBOOK In this lab, you will practice basic data analysis in Excel and explore some of the most common calculations used to tell data-driven stories and produce basic analysis of trends. After completing this lab, you will be able to use Excel to: Calculate sums Calculate rates Calculate percentages Contents Scenario... Error! Bookmark not defined. Task 1: Calculating Sums... 2 Task 2: Calculating Rates... 4 Using Ratios... 8 Task 3: Calculating Percentages... 9 Exercise... 11

3 Lab 1: Calculating Sums, Rates, and Percentages in Excel 2 Scenario In this lab, you will use Microsoft Excel to analyze a dataset about the number of midwives and health visitors across Sudan from the perspective of data journalist. Since regions in Sudan have varying population, you will analyze this data in a manner that these numbers can be compared across regions in a logical manner. You will also analyze data from specific regions to find out how it compares to the overall picture in Sudan. Task 1: Calculating Sums A basic step for analyzing a dataset is to calculate sums. In this task, you will calculate the total number of health visitors, midwives, and people in Sudan. To calculate sums, you can use AutoSum ( ) in Excel. Alternatively, you can also use a formula. Steps 1. Open Midwives_Health_Visitors_2013.XLSX in Excel. 2. In cell A19, type Sudan to indicate that this row will contain totals for the country. 3. In cell B19, type in formula to sum numbers =SUM(B2:B18), and press Enter. Note that in the formula =SUM(B2:B18), B2 is the first cell and B18 is the last cell in the series to add. The colon (:) tells Excel to include all cells between these two cells that you have identified. If you would use a comma (,) - Excel will include ONLY use the two cells identified.

4 Lab 1: Calculating Sums, Rates, and Percentages in Excel 3 4. Now that you have summed numbers in column B, you also need to sum columns C and D. Excel is smart. You don t have to type the formula in for each column. Instead, hover over the bottom right corner of cell B19 until a black cross appears. Click and hold, dragging across the columns in row 19. You should now have sums health visitors, midwives, and population across Sudan in row 19.

5 Lab 1: Calculating Sums, Rates, and Percentages in Excel 4 Task 2: Calculating Rates Can you compare two regions one where population is very large and another where the population is small just by looking at the totals? Often, the most logical way to compare numbers is through rates. For example, maternal deaths per 1,000 live births. In this task, we want to calculate the rate of Midwives and Health Visitors per 100,000 across the regions in Sudan. 5. In cell E1, enter the column label Groups of 100, In column E, you want to calculate how many groups of 100,000 are there in each region. This means you simply need divide the population of all regions by 100,000. In cell E2, type =D2/100000, and press Enter.

6 Lab 1: Calculating Sums, Rates, and Percentages in Excel 5 Next, hover over the bottom right corner of cell E2 until a black cross appears. Click and hold, dragging across the rows in column E. In cell E11, the result for Northern should be In other words, there are 8.13 sets of 100,000 people in Northern. 7. Next, in cell F1 - add a column label called Health Visitors per 100, To calculate this rate in column F, simply divide the total number of Health Visitors (column B) by Groups of 100,000 (column E). In cell F2, type =B2/E2 and press Enter.

7 Lab 1: Calculating Sums, Rates, and Percentages in Excel 6 Next, hover over the bottom right corner of cell F2 until a black cross appears. Click and hold, dragging across the rows in column F. In cell F11, the number is 0.86, which means there is less than one Health Visitor per 100,000 people in Northern. Meanwhile, since the dataset is missing the values for number of Health Visitors and Midwives for C. Darfour and E. Darfour Excel displays #VALUE! 9. In cell G1, add another column label called Mid Wives per 100,000 in this column, repeat a similar calculation - this time divide Mid wives by Groups of 100,000. In cell G2, type =C2/E2 and press Enter. Next, hover over the bottom right corner of cell G2 until a black cross appears. Click and hold, dragging across the rows in column G.

8 Lab 1: Calculating Sums, Rates, and Percentages in Excel 7 Now that you have calculated the ratios, answer the following questions: Which regions have the highest and lowest rate of Health Visitors per 100,000? Which regions have the highest and lowest number of Mid Wives per 100,000?

9 Lab 1: Calculating Sums, Rates, and Percentages in Excel 8 Using Ratios In order to make the comparisons easier to communicate, you can use a ratio. Say you want the public to compare the number of midwives in the region that has the highest rate, North Darfur (60.0) and the least, South Darfur (26.7). Will it be simple for your audience to understand the comparison between these two numbers: 60.0 and 26.7? You can calculate ratios to make this simple. First, divide each number by two. So, you have North Darfur = 30 and South Darfur = 13. Now, we know 30 and 12 are divisible by 6, and 13 is close to 12. So divide both by 6. Now we get North Darfur = 5 and South Darfur = 2.2. Hence we can say: For every 5 midwives in North Darfur, there are only 2 in South Darfur.

10 Lab 1: Calculating Sums, Rates, and Percentages in Excel 9 Task 3: Calculating Percentages Percentages can be useful for determining how big a number really is by looking at it as part of the whole. Let s figure out what percentage of total midwives in Sudan live in the region with the most midwives, Gazeria. In other words, you need to divide MidWives in Gazeria (value in cell C6) by Midwives in Sudan (value in cell C19). To do this in Excel: 10. In cell H1, add a label called Percentage of Midwives 11. In cell H6 (the row for Gazeria), enter the formula =C6/$C$19 and press Enter. Why did we use $C$19 instead of C19 like in the previous tasks? Because to replicate this formula across the column by dragging it, you need to first ensure that the denominator value (in cell C19) which represents the total number of Midwives in Sudan remains the same in each calculation. If you don t lock this value, the calculation won t work. Therefore, to lock the denominator, you type $ before C and before 19. So it says =C6/$C$19 Next, hover over the bottom right corner of cell H6 until a black cross appears. Click and hold, dragging across the rows in column H. 12. Now select the values in column H and right click, and then select Format Cells.

11 Lab 1: Calculating Sums, Rates, and Percentages in Excel 10 Next from the menu on the left, select Percentage and then click OK. You can now see that 2.02% of Sudan s midwives live in Khartoum

12 Lab 1: Calculating Sums, Rates, and Percentages in Excel 11 Exercise Use Excel to calculate the following: Calculate what percentage of Sudan s population lives in Gazeria Calculate what percentage of Sudan s population lives the rest of the country