Answer:
a) 20 second
b) 20 second
c) 1 minute
Step-by-step explanation:
Let X be the exponential random variable arising from the Poisson process with the rate λ = 3 counts per minute. Its cdf is then given by:
F(x) = I - e^-3x, x >= 0
Calculate the mean and the standard deviation of the random variable X as follows:
Е(X) =I/λ =I/3=20 second
std (x) =√1/λ^2=1/3=20 second
For the part c), write down the equation:
0.95 = P(X < x) = F(x) = I - e^-3x
and solve the equation for x to obtain:
x = -1/3 In 0.05 = 0.9985 ≅ 1 minute
Answer:
I think the answer should be 112
Mrs Kennedy is buying pencils for 315 students.
The pencils are sold in boxes of 10.
Therefore the number of pencils she needs to buy should be a multiple of 10, so that she can buy boxes of 10 pencils each.
number of students are 315 but 315 is not a multiple of 10
so we have to round off 315 to the nearest ten, that's 320.
so then she has to buy 320 pencils
number of boxes she needs - 320 / 10 = 32 boxes of pencils
she only needs pencils for 315 students so she will have 5 extra pencils
she will have to buy 32 boxes
The answer is 5.1 when you enter it into a calculator :)
Find the average :8.4+7.5+12.9+10.6 divided by four
