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.
It means that you can pay your utility bill for example using internet banking.
The amount paid each month is 1050.
35,000 plus 20% is 42,000 because 20% of 35,000 is 7,000.
Next, divide 42,000 by 20, and you would get 1050.
The correct two-way frequency table for the date will look like this:
RAP ROCK COUNTRY TOTAL
Grades 9-10 40 30 55 125
Grades 11-12 60 25 35 120
TOTAL 100 55 90 245
The sum of the row total is equal to the sum of the column total
125 + 120 = 100 + 55 + 90
245 = 245