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:

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:

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

0% probability that on a given day, 50 radioactive atoms decayed.
Answer:
32 People
Step-by-step explanation:
I put 40 (Number of birthday cards bought previously) over 125 (Number of expected costumers) and multiplied it by 100 (Total number of card bought previously) to get my answer. Hopefully that helps :)
Answer:
12. 9
Step-by-step explanation:
12. Using Pythagoras theorem
let shortest distance be = x
8 square + 5 square = x square
64 + 25 = x square
89 = x square
Therefore x = square root of 89
Thus X = 9
Answer:
b
Step-by-step explanation: