BACCALAURÉAT GÉNÉRAL ET TECHNOLOGIQUE SESSION 2009 ÉPREUVE SPÉCIFIQUE MENTION « SECTION EUROPÉENNE OU DE LANGUE ORIENTALE »
Académies de Paris-Créteil-Versailles Binôme : Anglais / Mathématiques Sujet 2 STATISTICS
The first part of this page is a summary that can be helpful to do the exercise. A frequency distribution is recorded in a frequency table. The values of the variable are often grouped into classes. The frequency table gives the possible values or class intervals of the variable and the corresponding frequencies. A histogram illustrates a frequency distribution. It consists of rectangles drawn on a continuous base. The area of each rectangle is proportional to the frequency of the class it represents. The rectangles do not have to be of equal width but their bases must be proportional to the class widths. The median is the value of the variable which stands in the middle of the distribution when the values are arranged in order of size. For a grouped frequency distribution, a good approximation to the median can be read off the cumulative frequency curve.
EXERCISE: The histogram below shows the distribution of midday temperatures in Celsius degrees in Northampton for the first 120 days of a year (the months January, February, March and April).
Represents 1 day
– 10
–4
0 4 Degrees Celsius
10
18
20
1) Why does this chart not need a vertical scale? 2) On how many days was the temperature lower than 0°C? 3) Estimate the number of days on which the temperature was higher than 12°C. 4) Using a cumulative frequency graph, estimate the median temperature for this period. 5) Make a frequency table and use it to find the mean daily temperature. Page : 1/1