Answer:
a) For this case we can use the definition of weighted average given by:
[tex] M = \frac{ \bar X_1 n_1 + \bar X_2 n_2}{n_1 +n_2}[/tex]
And if we replace the values given we have:
[tex] M = \frac{8*4 + 16*4}{4+4}= 12[/tex]
b) [tex] M = \frac{8*3 + 16*5}{3+5}= 13[/tex]
c) [tex] M = \frac{8*5 + 16*3}{5+3}= 11[/tex]
Step-by-step explanation:
Assuming the following question: "One sample has a mean of M=8 and a second sample has a mean of M=16 . The two samples are combined into a single set of scores.
a) What is the mean for the combined set if both of the original samples have n=4 scores "
For this case we can use the definition of weighted average given by:
[tex] M = \frac{ \bar X_1 n_1 + \bar X_2 n_2}{n_1 +n_2}[/tex]
And if we replace the values given we have:
[tex] M = \frac{8*4 + 16*4}{4+4}= 12[/tex]
b) what is the mean for the combined set if the first sample has n=3 and the second sample has n=5
Using the definition we have:
[tex] M = \frac{8*3 + 16*5}{3+5}= 13[/tex]
c) what is the mean for the combined set if the first sample has n=5 and the second sample has n=3
Using the definition we have:
[tex] M = \frac{8*5 + 16*3}{5+3}= 11[/tex]