Step 1: Determine the dataset's total sum. The formula for the average is:
Average = $\frac{\text{Sum of all values}}{\text{Total number of values}}$.
Let A and B denote the obscured values, with A + B = 18 (as per Question 20). The eleven known values are:
5, 6, 7, 8, 12, 16, 19, 21, 21, 27, 29.
The sum of these eleven known values is:
5 + 6 + 7 + 8 + 12 + 16 + 19 + 21 + 21 + 27 + 29 = 171.
Step 2: Compute the total sum including A and B. The complete total sum is:
Total Sum = 171 + A + B = 171 + 18 = 189.
Step 3: Calculate the average.
Average = $\frac{189}{13} = 13$.
Final Answer: 13.
Step 1: Determine the total recalculated sum. The recalculated average is 15. Using the formula for average:
Average = $\frac{\text{Sum of all values}}{\text{Total number of values}}$
15 = $\frac{\text{Recalculated Total Sum}}{13}$
Therefore:
Recalculated Total Sum = 15 × 13 = 195.
Step 2: Calculate the correction applied. The original sum of the eleven known values was 171. After adding A and B, the total becomes:
171 + A + B = 171 + 18 = 189.
The recalculated total sum is 195, so the difference due to the correction is:
195 − 189 = 6.
This indicates one recorded value was half of its correct value. Let the incorrect value be x. Then:
$\frac{x}{2}$ + 6 = x. Solving for x yields x = 12.
Step 3: Solve for B. Given A + B = 18 from Question 20. If A = 6, then:
B = 18 − 6 = 9.
Final Answer: 9.
A pie chart shows the allocation of a 260 lakh annual budget among 5 departments. If the Health department gets 18% and Education gets 24%, how much more does Education get than Health? 
A pie chart shows the distribution of students across 5 faculties in a university. If 20% are in Arts, 25% in Science, 15% in Law, 30% in Engineering, and the rest in Commerce, what is the angle (in degrees) for Commerce?
A bar graph shows the number of students in 5 departments of a college. If the average number of students is 240 and the number of students in the Science department is 320, how many students are there in total in the other four departments?