Florence Nightingale (1820-1910) is mostly known because of her work as a nurse during the Crimean War and her contribution to the reform in sanitary conditions at military hospitals. She is considered the mother of modern nursing and the creator of the first conceptual model of nursing. From a very young age she stood out in mathematics, and later on she applied her knowledge on statistics to epidemiology and to health statistics. She was the first woman to be admitted at the British Royal Statistical Society, and she was an honorary member of the American Statistical Association.

We propose the following statistics problem:

The following table shows the number of siblings that the students of a group have.

Please answer the following questions:

1. How many students are there in the group?
2. Complete the table with the relative frequencies, the percentages and the degrees that correspond to each datum in a pie chart.
3. Draw the corresponding bar and pie charts.
4. Calculate the arithmetic mean and the mode.