What is a Pie Chart?

Summary

This video tutorial explains the process of creating a pie chart using a real-life example of jacket sizes for a girls' basketball team. It walks through organizing the data, calculating the degrees and percentages for each section, and verifying the results. By showing how to divide 360 degrees among different categories (XS, S, M, L), the video provides a clear understanding of pie charts, from data preparation to drawing the chart. It’s an engaging and informative guide for beginners looking to learn about pie chart creation and interpretation.

Takeaways

• 😀 A pie chart is a type of graph that divides data into slices, similar to a pizza, with each slice representing a percentage of the total.
• 😀 The values in a pie chart are expressed as percentages, which are calculated based on the total number of items in the dataset.
• 😀 In the example, the coach organizes data into a table, recording sizes (extra small, small, medium, and large) and the number of players who wear each size.
• 😀 The total number of players is 60, calculated by adding up the frequencies of each size (5 for extra small, 10 for small, 26 for medium, and 19 for large).
• 😀 To determine how much each slice represents in degrees, the total number of degrees in a circle (360 degrees) is divided by the total number of players.
• 😀 Each player corresponds to 6 degrees in the pie chart (360 degrees ÷ 60 players).
• 😀 The degree measurement for each size is calculated by multiplying the number of players by 6 degrees. For example, 5 players wearing extra small means 30 degrees (6 × 5).
• 😀 The degrees for each size are 30 for extra small, 60 for small, 156 for medium, and 114 for large, adding up to the full 360 degrees of the circle.
• 😀 Percentages for each size are calculated by multiplying the percentage of one player (1.7%) by the number of players wearing each size.
• 😀 The final percentages are approximately 8.5% for extra small, 17% for small, 44.2% for medium, and 32.3% for large, with the total summing close to 100%.
• 😀 The coach uses a protractor to draw the circle and mark the slices on the pie chart according to the calculated degrees, and labels each slice with its corresponding percentage.

Q & A

What is a pie chart and how is it different from other graphs?

A pie chart is a type of graph that is divided into slices, much like a pizza. Each slice represents a proportion of the whole, with the values for each slice expressed in percentages, which distinguishes it from other types of graphs.

How did the coach organize the data for the pie chart?

The coach organized the data into a table. The first column listed the jacket sizes (extra small, small, medium, and large), and the second column showed the frequency, or number of players, who wear each size. The total number of players was 60.

How does the coach calculate the degrees for each slice of the pie chart?

The coach divided 360 degrees by the total number of players (60) to find out that each player represents 6 degrees. Then, she multiplied 6 degrees by the number of players wearing each size to determine the size of each section in the pie chart.

What are the degrees for each size in the pie chart?

The degrees for each size are as follows: extra small is 30 degrees (6 x 5), small is 60 degrees (6 x 10), medium is 156 degrees (6 x 26), and large is 114 degrees (6 x 19).

How did the coach check if the degree calculations were correct?

The coach added up the degrees for each size (30 + 60 + 156 + 114) to make sure the total was 360 degrees, confirming that the calculations were correct.

How does the coach calculate the percentage for each size?

The coach calculated the percentage by multiplying 1.7% (which is the percentage each player represents) by the number of players in each size category. This gives the percentage for each size.

What are the percentages for each size?

The percentages for each size are as follows: extra small is 8.5%, small is 17%, medium is 44.2%, and large is 32.3%. These percentages may slightly exceed 100% due to rounding.

Why might the total percentage exceed 100%?

The total percentage may exceed 100% because the percentage for each player was estimated to be 1.7%. When decimals are approximated, slight rounding can cause the total to be a little higher than 100%.

How does the coach create the visual pie chart?

The coach uses a protractor to trace a circle and then divides it into sections based on the calculated degrees. Each section represents a different jacket size. After drawing the sections, the coach adds the percentages to make the chart easier to read.

Why is it important to add the percentages to each slice of the pie chart?

Adding the percentages to each slice helps viewers easily understand the proportion each jacket size represents in relation to the total number of players. It makes the chart more informative and easier to interpret.