The average of 15 observations is 29. if the average of first 8 observ

1.	The average of 15 observations is 29. if the average of first 8 observations is 27 and that of last 8 observations is 31. the what will be the 8th observation? 1. 272. 313. 304. 29
Answer» Correct Answer - Option 4 : 29 GIVEN: average of 15 observations = 29 average of first 8 = 27 average of last 8 = 31 FORMULA USED: average = sum of all observations/total number of observations CALCULATION: sum of 15 observations = 15 × 29 = 435 sum of first 8 observations = 8 × 27 = 216 sum of last 8 observations = 8 × 31 = 248 the 8th observation is repeated twice in sum of first and last observations 8th observation = (sum of first 8) + (sum of last 8) - (sum of 15 observations) ⇒ 216 + 248 - 435 = 29 ∴ 8th observation is 29

The average of 15 observations is 29. if the average of first 8 observations is 27 and that of last 8 observations is 31. the what will be the 8th observation? 1. 272. 313. 304. 29

Answer» Correct Answer - Option 4 : 29

GIVEN:

average of 15 observations = 29

average of first 8 = 27

average of last 8 = 31

FORMULA USED:

average = sum of all observations/total number of observations

CALCULATION:

sum of 15 observations = 15 × 29 = 435

sum of first 8 observations = 8 × 27 = 216

sum of last 8 observations = 8 × 31 = 248

the 8th observation is repeated twice in sum of first and last observations

8th observation = (sum of first 8) + (sum of last 8) - (sum of 15 observations)

⇒ 216 + 248 - 435 = 29

∴ 8th observation is 29

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