Question

In a class of 60 students, mathematics examination was conducted. All the students obtained 20 marks each. What would be the mean and standard deviation of marks in mathematics?

• A. 1200 and 20
• B. 120 and 1
• C. 20 and 0
• D. 20 and 60

Hint:

If all values in a dataset are identical, the standard deviation is always 0, indicating no spread or variability in the data.

Answer 1

The Correct Option is C

Step 1: Calculate the Mean. 
All 60 students scored 20 marks. 
Mean \( = \frac{{Sum of all scores}}{{Number of students}} = \frac{60 \times 20}{60} = 20 \) 
Step 2: Calculate the Standard Deviation. 
Since all students have the same score (20), there is no variation. Standard Deviation \( = 0 \)