What is a Pie Chart

statistics basic concepts pie charts pie chart is type of graph that's divided into slices sort of like pizza unlike other graphs the values that make up each piece are expressed in percentages let's take look at an example at school the girls basketball teams are having jackets made for the Regional Championship the head coach wants to create pie chart that shows which Jacket sizes they'll need she starts off by organizing the data into table in the First Column she records the sizes extra small small medium and large in the second column she writes down the frequency or the number of players who wear each size five athletes wear an extra small 10 prefer small 26 for medium and 19 for large adding up these numbers gives us the total number of players on the girls teams 60. she now needs to figure out how many degrees will each size make up in the circle of the pie chart we know that circle has 360 degrees if 360 is divided by the total number of players this tells us that one athlete equals 6 degrees if we multiply 6 degrees by the number of players wearing each size this tells us how big each section of the pie chart should be for example 6 times 5 equals Thirty so the extra small section should be 30 degrees in the circle 6 times 10 is 60. 60 degrees for size small 6 times 26 is 156. size medium will be 156 degrees and 6 times 19 equals 114 degrees for size large to double check her division the coach adds up the numbers in the degrees column this equals 360 Degrees which means that her calculations are correct finally she adds fourth column which will show the percent of each size if hundred percent represents the total and this is divided among 60 players this means that each athlete equals roughly 1.7 percent of the team so let's multiply 1.7 by the number of players wearing each size to determine the percentages 1.7 times 5 equals 8.5 percent 1.7 times 10 is 17 percent 1.7 times 26 is 44.2 percent and 1.7 times 19 is 32.3 percent the sum of this column should be approximately hundred percent since 1.7 percent was an estimate it's okay if it goes little over this happens when decimals are approximated in division now that the table is complete the coach begins making her graph she traces her protractor to draw circle then uses it to make the first 30 degree section for size extra small next up is 60 degrees for size small 156 degrees for size medium and 114 degrees for size large finally she adds the percentage to each slice of the pie making the chart easier to read feel free to check out our other videos about statistics are the full tutorial on our website at gcfglobal.org GCF global creating opportunities for better life