I see you've uploaded a photo with several statistical exercises in French. Let me guide you through each part of the document.

Exercise 1: Histogram of "Notes sur 5"

1. The histogram shows a distribution of grades from 1 to 9.

2. The questions are: a) What is the total number of students?

   • You sum the values from the histogram.

   b) What percentage got a grade of 5?

   • The frequency for grade 5 divided by the total number of students.

   c) How many students got a grade below 5?

   • Sum the frequencies for grades below 5.

   d) Reproduce this data in a statistical diagram (likely asking for another graph or table summarizing the frequencies).

Exercise 2: Circle Graph (Automobile Colors)

1. The pie chart shows the color distribution of 500 cars. The sectors are for colors Green (180°), Orange (120°), and Red (60°).
2. The question is:
   • Determine the number of green cars.
     • Since the total is 500 cars, and the green sector is 180°, you can calculate this by the proportion $\frac{180°}{360°} \times 500$.

Exercise 3: Another Histogram (Factory Quality Control)

1. A histogram represents data on the quality control of fabricated electrical boxes.

2. The questions are: a) What is the total number of defective boxes?

   • You sum the values from the histogram.

   b) What percentage of the boxes are defective?

   • Percentage calculation using the total number from the histogram and the total number of boxes.

Would you like me to walk through the solutions to each part, or do you have any specific questions about these exercises?

Here are some related questions for practice:

1. How would you calculate the mean grade from Exercise 1?
2. What method would you use to calculate the median grade from the histogram?
3. How can you convert the pie chart angles into percentages?
4. What is the variance of the grades in Exercise 1, if given the full dataset?
5. What are the limitations of using a histogram versus a pie chart for data analysis?

Tip: When dealing with percentages, always ensure that the total values are correct and consistent before calculating individual proportions.