Answer:
The probability is 0.0428
Step-by-step explanation:
First, let's remember that the binomial distribution is given by the formula:
![P(X=k) =\left[\begin{array}{ccc}n\\k\end{array}\right] p^{k}(1-p)^{n-k}](https://tex.z-dn.net/?f=P%28X%3Dk%29%20%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dn%5C%5Ck%5Cend%7Barray%7D%5Cright%5D%20p%5E%7Bk%7D%281-p%29%5E%7Bn-k%7D)
where k is the number of successes in n trials and p is the probability of success.
However, the problem tells us that when there isn't a number of trials fixed, we can use the geometric distribution and the formula for getting the first success on the xth trial becomes:
The problem asks us to find the probability of the first success on the 4th trial (given that the first subject to be a universal blood donor will be the fourth person selected)
Using this formula with the parameters given, we have:
p = 0.05
x = 4
Substituting these parameters in the formula and solving it, we get:
Therefore, the probability that the first subject to be a universal blood donor is the fourth person selected is 0.0428 or 4.28%
Answer:
C) 60
Step-by-step explanation:
180 - 120
Answer: The waiting time will be 32 minutes when 240 people in line.
Step-by-step explanation:
Let us assume that the waiting time is directly proportional to the number of people in the queue.
Equation of direct proportion between variables x and y : 
Put 
to find 
.
Hence, the waiting time will be 32 minutes when 240 people in line.
Answer:
A) 24
Step-by-step explanation:
4!
4 x 3 x 2 x 1
24
To find explicit formulas, you need two things. The common difference and the first term.
For example, #18
The first term = -15
The common difference = -20 -(-15) = -20 + 15 = -5
y = A + B(n - 1)
A = our first term
B = our common difference
n = the term you want to find in the sequence.
Leta plug our numbers in from #18
y = -15 + -5(n - 1)
Let's find the 4th term in the sequence.
y = -15 + -5(4 - 1)
y = -15 + -5(3)
y = -15 + -15
y = -30
