Respuesta :
Answer:
16.5 year
Step-by-step explanation:
Using, mean = sum/no. *of observations
Here,
=> 16.2 = (sum of ages of boys)/18
=> 16.2 x 18 = sum of ages of boys
=> 291.6 = sum of ages of boys
Similarly, sum of ages of girls = 27 x 16.7 = 450.9
Mean(total) = (sumof agesof boys + girls)/45
Mean = (291.6 + 450.9)/45 = 16.5
Answer:
The mean age of all 45 boys and girls is 16.5years
Step-by-step explanation:
Since the mean age of the 18 boys is 16.2years,
∴ Sum of their ages = 18 × 16.2
= 291.6years
The mean age of the 27 girls is 16.7years
∴ Sum of their ages = 27 × 16.7
= 450.9years
∴ Mean age of all 45 boys and girls = [tex]\frac{291.6 + 450.9}{45}[/tex] years
= [tex]\frac{742.5}{45}[/tex] years
= 16.5 years
∴ The mean age of all 45 boys and girls is 16.5 years.