1. The first question asks to make a scatter diagram of the marks before and after coaching for 10 students. 2. Scatter diagrams plot pairs of data points to show relationships between two variables. 3. Here, the x-values are marks before coaching: $[25, 23, 19, 22, 21, 19, 22, 21, 25, 18]$. 4. The y-values are marks after coaching: $[26, 22, 22, 19, 23, 21, 24, 24, 25, 22]$. 5. Plot each student as a point $(x, y)$ where $x$ is marks before and $y$ is marks after. 6. This scatter plot helps visualize if coaching improved marks (points above the line $y=x$ indicate improvement). 7. Since the user requested all questions but per guest rule only the first is solved, we stop here. Final answer: The scatter diagram consists of points $(25,26), (23,22), (19,22), (22,19), (21,23), (19,21), (22,24), (21,24), (25,25), (18,22)$ showing the relationship between marks before and after coaching.