The mean of 15 observations is 21.2. If the mean of the first
seven observations is 18.5, and that of the last seven
observations is 22.5, then the value of the 8th observation is
Answers
Answer:
31
Step-by-step explanation:
Firstly find the total number of obsevations of all 15
Mean = total obsevations ÷ number of obsevations
21.2 = Total ÷ 15
Total = 15 × 21.2
Total = 318
Now find the total Obsevations of first seven
Mean = Total observations ÷ number of observations
18.5 = Total ÷ 7
Total = 18.5 × 7
Total = 129.5
Next, find the total obsevations of last seven
Mean = Total observations ÷ number of observations
22.5 = Total ÷ 7
Total = 22.5 × 7
Total = 157.5
Add the 14 observations together
Addition = 129.5 + 157.5
= 287
At last, subtract this addition from the main total to get the remaining observation
Remaining Obsevation = 318 - 287
= 31
So,
8th observation = 31
Answer:
Answer:
31
Step-by-step explanation:
Firstly find the total number of obsevations of all 15
Mean = total obsevations ÷ number of obsevations
21.2 = Total ÷ 15
Total = 15 × 21.2
Total = 318
Now find the total Obsevations of first seven
Mean = Total observations ÷ number of observations
18.5 = Total ÷ 7
Total = 18.5 × 7
Total = 129.5
Next, find the total obsevations of last seven
Mean = Total observations ÷ number of observations
22.5 = Total ÷ 7
Total = 22.5 × 7
Total = 157.5
Add the 14 observations together
Addition = 129.5 + 157.5
= 287
At last, subtract this addition from the main total to get the remaining observation
Remaining Obsevation = 318 - 287
= 31
So,
8th observation = 31