Answer:
11
Step-by-step explanation:
Given:
A collection of 8 backpacks has a mean weight of 14 pounds
A different collection of 12 backpacks has a mean weight of 9 pounds
Question asked:
What is the mean weight of the 20 backpacks ?
Solution:
For first collection of backpacks.
As we know:
![Mean = \frac{Sum\ of \ observations}{Total \ observations} \\](https://tex.z-dn.net/?f=Mean%20%3D%20%5Cfrac%7BSum%5C%20of%20%5C%20observations%7D%7BTotal%20%5C%20observations%7D%20%5C%5C)
![14=\frac{sum\ of \ observation}{8} \\14\times 8= Sum\ of \ observation\\112=Sum\ of \ observation\\](https://tex.z-dn.net/?f=14%3D%5Cfrac%7Bsum%5C%20of%20%5C%20observation%7D%7B8%7D%20%5C%5C14%5Ctimes%208%3D%20Sum%5C%20of%20%5C%20observation%5C%5C112%3DSum%5C%20of%20%5C%20observation%5C%5C)
For Second collection of backpacks.
![Mean = \frac{Sum\ of \ observations}{Total \ observations} \\](https://tex.z-dn.net/?f=Mean%20%3D%20%5Cfrac%7BSum%5C%20of%20%5C%20observations%7D%7BTotal%20%5C%20observations%7D%20%5C%5C)
![9=\frac{Sum \ of\ observations}{12} \\9\times12=Sum \ of\ observations\\108 = Sum \ of\ observations](https://tex.z-dn.net/?f=9%3D%5Cfrac%7BSum%20%5C%20of%5C%20observations%7D%7B12%7D%20%5C%5C9%5Ctimes12%3DSum%20%5C%20of%5C%20observations%5C%5C108%20%3D%20Sum%20%5C%20of%5C%20observations)
Now, we will find the mean weight of the 20 backpacks altogether.
<u>Mean weight of the 20 backpacks = Total sum of observations divided by total number of observations</u>
Combined Mean = ![\frac{112+108}{8+12} \\](https://tex.z-dn.net/?f=%5Cfrac%7B112%2B108%7D%7B8%2B12%7D%20%5C%5C)
=![\frac{220}{20} =11](https://tex.z-dn.net/?f=%5Cfrac%7B220%7D%7B20%7D%20%3D11)
Therefore, the mean weight of the 20 backpacks is 11.
Answer:
B. 2/3
Step-by-step explanation:
To solve this we have to take into account this axioms:
- The total probability is always equal to 1.
- The probability of a randomly selected point being inside the circle is equal to one minus the probability of being outside the circle.
Then, if the probabilities are proportional to the area, we have 1/3 probability of selecting a point inside a circle and (1-1/3)=2/3 probability of selecting a point that is outside the circle.
Then, the probabilty that a random selected point inside the square (the total probability space) and outside the circle is 2/3.
Option B is the correct answer, x+15=41
Answer:
red marble
Step-by-step explanation:
i did this yw
Answer:
D is the answers for the question
Step-by-step explanation:
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