Answer: 14 a hour
Step-by-step explanation:
Answer:
it's a sooooooo it's the first one
Answer:
probability that the child DOES NOT play the piano

Step-by-step explanation:
A students' choir contains 25 children
n(S) =25
The number of students play the piano =5
Let 'E' be the event of the child play the piano so n(E) =5
The probability of that the child play the piano


Let 'E⁻ be the event of the child play does not play the piano


<u>Conclusion</u>:-
probability that the child DOES NOT play the piano

Answer:
<em>x ∈ ( - ∞ , - 8 ) ∪ ( - 8 , 0 ) ∪ ( 0 , 8 ) ∪ ( 8 , ∞ ) </em>
Step-by-step explanation:
x³ - 64x = x( x² - 64 ) ≠ 0 ⇒ x ≠ 0 and x ≠ ± 8
<em>x ∈ ( - ∞ , - 8 ) ∪ ( - 8 , 0 ) ∪ ( 0 , 8 ) ∪ ( 8 , ∞ )</em>
Answer:

Now we can find the second moment with this formula:

And replacing we got:

The variance would be given by:
![Var(X) =E(X^2) -[E(X)]^2 = 21.4 -[3.8]^2 = 6.96](https://tex.z-dn.net/?f=%20Var%28X%29%20%3DE%28X%5E2%29%20-%5BE%28X%29%5D%5E2%20%3D%2021.4%20-%5B3.8%5D%5E2%20%3D%206.96)
And the deviation would be:

Step-by-step explanation:
For this case we have the following distribution given:
X 1 2 7
P(X) 1/5 2/5 2/5
We need to begin finding the mean with this formula:

And replacing we got:

Now we can find the second moment with this formula:

And replacing we got:

The variance would be given by:
![Var(X) =E(X^2) -[E(X)]^2 = 21.4 -[3.8]^2 = 6.96](https://tex.z-dn.net/?f=%20Var%28X%29%20%3DE%28X%5E2%29%20-%5BE%28X%29%5D%5E2%20%3D%2021.4%20-%5B3.8%5D%5E2%20%3D%206.96)
And the deviation would be:
