Across the six given years, what is the difference between the average number…

Concept

The average of n observations is their total divided by n.

When two data series have the same number of observations, the absolute difference between their averages equals the absolute difference between their totals divided by n.

Application

1. Office D total: 240 + 224 + 248 + 270 + 236 + 258 = 1,476.

2. Office E total: 280 + 304 + 316 + 332 + 340 + 348 = 1,920.

3. Average for office D = 1,476 ÷ 6 = 246 employees.

4. Average for office E = 1,920 ÷ 6 = 320 employees.

5. Difference between the averages = |320 − 246| = 74 employees.

Cross-check

The difference between the six-year totals is 1,920 − 1,476 = 444. Dividing this by the common count of six years gives 444 ÷ 6 = 74, confirming the result.

Result

The difference is 74 employees.