It would take him 12 days.
1/3 x 3 = 3
3x4=12
The Poisson distribution is a discrete distribution that calculates the likelihood that a certain number of events will occur within a certain amount of time.
The probability of getting exactly three robberies in a day is 0.1607.
<h3>What is meant by poison distribution?</h3>
The Poisson distribution is a discrete probability distribution used in probability theory and statistics to express the likelihood that a given number of events will occur within a specified time or space interval if they occur at a known constant mean rate and regardless of the interval since the last event.
The Poisson distribution is a discrete distribution that calculates the likelihood that a certain number of events will occur within a certain amount of time.
In the poison distribution a discrete random variable X has the following probability mass function,
, where
is the mean of the distribution and
Given that 
The required probability, 
Therefore, the probability of getting exactly three robberies in a day is = 0.1607.
To learn more about poison distribution refer to:
brainly.com/question/9123296
#SPJ9
cos (2x) = cos x
2 cos^2 x -1 = cos x using the double angle formula
2 cos ^2 x -cos x -1 =0
factor
(2 cos x+1) ( cos x -1) = 0
using the zero product property
2 cos x+1 =0 cos x -1 =0
2 cos x = -1 cos x =1
cos x = -1/2 cos x=1
taking the arccos of each side
arccos cos x = arccos (-1/2) arccos cos x = arccos 1
x = 120 degrees x=-120 degrees x=0
remember you get 2 values ( 2nd and 3rd quadrant)
these are the principal values
now we need to add 360
x = 120+ 360n x=-120+ 360n x = 0 + 360n where n is an integer
Answer:
i think b. at least one of them contracted a lung disease
Answer:
5x+17
Step-by-step explanation:
2(x+7) + 3(x+1)
- Distribute(Expand) -> 2x+14 + 3x+3
- Simplify by combining like terms -> 5x+17