Statistics-And-Probability Question 620
Question: If the combined mean of two groups is $ \frac{40}{3} $ and if the mean of one group with 10 observations is 15, then the mean of the other group with 8 observation is equal to
Options:
A) $ \frac{46}{3} $
B) $ \frac{35}{4} $
C) $ \frac{45}{4} $
D) $ \frac{41}{4} $
Show Answer
Answer:
Correct Answer: C
Solution:
[c] Let total no. of obs $ =18 $ Let mean of one group $ =a_1=15 $ And mean of other group $ =a_2 $ Given: Combined mean $ =\frac{40}{3} $ Now, combined mean $ =\frac{(a_1\times 10)+(a_2\times 5)}{18} $
$ \Rightarrow \frac{40}{3}=\frac{150+8a_2}{18}\Rightarrow a_2=\frac{45}{4} $
BETA
