Answer:
a) The mean number of radioactive atoms that decay per day is 81.485.
b) 0% probability that on a given day, 50 radioactive atoms decayed.
Step-by-step explanation:
Poisson distribution:
In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by the following formula:
![P(X = x) = \frac{e^{-\lambda}*\lambda^{x}}{(x)!}](https://tex.z-dn.net/?f=P%28X%20%3D%20x%29%20%3D%20%5Cfrac%7Be%5E%7B-%5Clambda%7D%2A%5Clambda%5E%7Bx%7D%7D%7B%28x%29%21%7D)
In which
x is the number of sucesses
e = 2.71828 is the Euler number
is the mean in the given interval.
a. Find the mean number of radioactive atoms that decayed in a day.
29,742 atoms decayed during 365 days, which means that:
![\lambda = \frac{29742}{365} = 81.485](https://tex.z-dn.net/?f=%5Clambda%20%3D%20%5Cfrac%7B29742%7D%7B365%7D%20%3D%2081.485)
The mean number of radioactive atoms that decay per day is 81.485.
b. Find the probability that on a given day, 50 radioactive atoms decayed.
This is P(X = 50). So
![P(X = 50) = \frac{e^{-81.485}*(81.485)^{50}}{(50)!} = 0](https://tex.z-dn.net/?f=P%28X%20%3D%2050%29%20%3D%20%5Cfrac%7Be%5E%7B-81.485%7D%2A%2881.485%29%5E%7B50%7D%7D%7B%2850%29%21%7D%20%3D%200)
0% probability that on a given day, 50 radioactive atoms decayed.
A lot like shoot i think 20 or more
![- 8x + 5 = - 8x + 4 \\ - 8x = - 8x + 4 - 5 \\ - 8x = - 8x - 1 \\ 0 = - 1(false)](https://tex.z-dn.net/?f=-%208x%20%2B%205%20%3D%20%20-%208x%20%2B%204%20%5C%5C%20%20%20-%208x%20%3D%20%20-%208x%20%2B%204%20-%205%20%5C%5C%20%20-%208x%20%3D%20%20-%208x%20-%201%20%5C%5C%20%200%20%3D%20%20-%201%28false%29)
we don't have solutions !!
Step-by-step explanation:
x=−y−2z+3
x=y+32z+1
x=13y+23z+13
Here, you just want to solve it by finding a common denominator.
1/5+2/7, because she read 1/5 and 2/7 of the book on separate days. The common denominator is 35.
7/35+10/35
=17/35
So that's how much of the book she read before Saturday.
Now it says that on Sunday she read 5/9 of the remaining pages, meaning:
1-17/35 should give us our answer
35/35-17/35=18/35
But since it says she read 5/9 of the remaining pages, we need to multiply 18/35 by 5/9 to get what 5/9ths of 18/35 is.
(18/35)(5/9)=2/7
Therefore she read 2/7ths of the book on Sunday.