Answer:
1.25
Step-by-step explanation:
I did this question before and got it right
Answer: 
Step-by-step explanation:
^{2} +(-3-3)^{2} \\\sqrt64+36\\\sqrt100\\=10](https://tex.z-dn.net/?f=%5Csqrt%5Bn%5D%28-4-4%29%5E%7B2%7D%20%2B%28-3-3%29%5E%7B2%7D%20%5C%5C%5Csqrt64%2B36%5C%5C%5Csqrt100%5C%5C%3D10)
Answer:
<u>135.73 ounces</u> of a silver alloy that costs $5.50 per ounce should be mixed.
Step-by-step explanation:
Given:
A silver alloy that costs $5.50 per ounce should be mixed with one that costs $7.00 per ounce to make a new 30 ounce alloy that costs $6.40 per ounce.
Now, to find the ounces of silver alloy.
Let the silver costs $5.50 per ounce be 
And the silver costs $7.00 per ounce be 
So, the total ounce make a new alloy:
....(1)
Now, the total costs of silver alloy:

Putting the value of
from equation (1) in the place of
:



<em>Subtracting both sides by 210 we get:</em>

<em>Dividing both sides by -1.5 we get:</em>

Therefore, 135.73 ounces of a silver alloy that costs $5.50 per ounce should be mixed.
The mean of this discrete random variable is 7.96
<em><u>Solution:</u></em>
Given that,
x 4 6 9 11 15
P(x) 0.20 0.34 0.15 0.22 0.09
<u><em>Mean is given as:</em></u>
![\mu_{x}=\sum[x \times P(x)]](https://tex.z-dn.net/?f=%5Cmu_%7Bx%7D%3D%5Csum%5Bx%20%5Ctimes%20P%28x%29%5D)
Therefore,

Thus, mean of this discrete random variable is 7.96