Correct Answer - Option 1 : 23°
Given:
The average temperature of 4 months is 20°
Formula used:
Sum of observations = average × numbers of observations
Calculation:
Total temperature of 4 months = 4 × 20° = 80°
Correct total temperature = 80° - 12° + 24° = 92°
∴ Correct average temperature of 4 months = 92° / 4 = 23°
Short trick:
Change in temperature because of 12° and 24° ∴ change = - 12° + 24° = 12°
∴ Change per month = 12°/ 4 = 3°
Correct average temperature of 4 months = 20° + 3° = 23°
