- LPU MCA Semester 1
- PEA515
- Unit 7
PEA515 · Unit 7: Data interpretation
Data interpretation concepts, tabulation, average and percentage
30 practice questions · in the ETE syllabus
Key points
- Average = sum / count
- Percentage change uses the old value as base
- Share = part / total of the same row
- Compare differences year by year
A table lists values by rows and columns. Read the question carefully for which row or column it asks about, and for the unit.
| Quantity | Formula |
|---|---|
| Average | Sum of values / number of values |
| Percentage share | Part / total of the same row (or column) x 100 |
| Percentage change | (new - old) / old x 100 |
| Ratio of two columns | Total of one : total of the other, reduced |
| Greatest difference | Compute the difference for every row, then compare |
Example: a column holds 280, 240, 100 and 40 over four years, so the average is 660 / 4 = 165. A rise from 80 to 112 is a 32 / 80 = 40% increase. If the values for a year are 80, 60 and 70 (total 200), the third is 70 / 200 = 35% of that year.
Work out only what the question needs. Estimating or rounding at each step can mislead, so keep exact numbers until the end.
Exam trap: percentage change always uses the earlier value as the base, and a share uses the total of the same year, not the column total.