Solve the unknown variable
1 answer:
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Answer:
The probability is 0.0428
Step-by-step explanation:
First, let's remember that the binomial distribution is given by the formula:
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:
5.36
Step-by-step explanation:
Given that:
<BAD = <CAE, therefore, BD = EC
Let's take x to be the length of BD = EC
BD + DE + EC = BC
BC = 20,
BD = EC = x
DE ≈ 9.28
Thus,
x + 9.28 + x = 20
x + x + 9.28 = 20
2x + 9.28 = 20
Subtract 9.28 from both sides
2x + 9.28 - 9.28 = 20 - 9.28
2x = 10.72
Divided both sides by 2 to solve for x
BD ≈ 5.36