During a flu epidemic,170 students out of the 680 who attend Lincoln Middle School were absent .What percent were present?
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:
b = 90
Step-by-step explanation:
Sum the interior angles of the pentagon and equate to 540
Starting from the top and going clockwise
b + b + 45 + 90 + 2b - 90 + b = 540 ← simplify left side
b + 45 = 540 ( multiply through by 2 to clear the fraction )
11b + 90 = 1080 ( subtract 90 from both sides )
11b = 990 ( divide both sides by 11 )
b = 90
Thus
b + 45 = 90 + 45 = 135
2b - 90 = 2(90) - 90 = 180 - 90 = 90
b =
× 90 = 135
The angle measure from the top clockwise are
90°, 135°, 90°, 90°, 135°