Answer:
a) For this case we can use the definition of weighted average given by:
And if we replace the values given we have:
b)
c)
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:
And if we replace the values given we have:
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:
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:
Answer: the cost of one daylilies is $4
the cost of one ivy is $9
Step-by-step explanation:
Let x represent the cost of one daylilies.
Let y represent the cost of one ivy.
Nicole and Kim bought their supplies from the same store. Nicole spent $99 on 9 daylilies and 7 pots of ivy. This means that
9x + 7y = 99 - - - - - - - -1
Kim spent $144 on 9 daylilies and 12 pots of ivy. This means that
9x + 12y = 144 - - - - - - - - -2
We will eliminate x by subtracting equation 2 from equation 1, it becomes
- 5y = - 45
y = - 45/-5 = 9
Substituting y = 9 into equation 2, it becomes
9x + 12 × 9 = 144
9x + 108 = 144
9x = 144 - 108 = 36
x = 36/9 = 4
1. 9 5/185 or 9 1/37
2. 25 6/406 or 25 3/203
Answer =1
6x+2=9x-1
-3x=-3
X=1