Can someone pls help me out on the middle one pls ?:(

Among persons donating blood to a clinic, 85% have Rh+ blood (that is, the Rhesus factor is present in their blood.) Six people

Leona [35]

Answer:

a) There is a 62.29% probability that at least one of the five does not have the Rh factor.

b) There is a 22.36% probability that at most four of the six have Rh+ blood.

c) There need to be at least 8 people to have the probability of obtaining blood from at least six Rh+ donors over 0.95.

Step-by-step explanation:

For each person donating blood, there are only two possible outcomes. Either they have Rh+ blood, or they do not. This means that we use the binomial probability distribution to solve this problem.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinatios of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

In this problem we have that:

$p = 0.85, n = 6$ .

a) fine the probability that at least one of the five does not have the Rh factor.

Either all six have the factor, or at least one of them do not. The sum of the probabilities of these events is decimal 1. So:

$P(X < 6) + P(X = 6) = 1$

$P(X < 6) = 1 - P(X = 6)$

In which:

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 6) = C_{6,6}.(0.85)^{6}.(0.15)^{0} = 0.3771$

So

$P(X < 6) = 1 - P(X = 6) = 1 - 0.3771 = 0.6229$

There is a 62.29% probability that at least one of the five does not have the Rh factor.

b) find the probability that at most four of the six have Rh+ blood.

Either more than four have Rh+ blood, or at most four have. So

$P(X \leq 4) + P(X > 4) = 1$

$P(X \leq 4) = 1 - P(X > 4)$

In which

$P(X > 4) = P(X = 5) + P(X = 6)$

$P(X = 5) = C_{6,5}.(0.85)^{5}.(0.15)^{1} = 0.3993$

$P(X = 6) = C_{6,6}.(0.85)^{6}.(0.15)^{0} = 0.3771$

$P(X > 4) = P(X = 5) + P(X = 6) = 0.3993 + 0.3771 = 0.7764$

$P(X \leq 4) = 1 - P(X > 4) = 1 - 0.7764 = 0.2236$

There is a 22.36% probability that at most four of the six have Rh+ blood.

c) The clinic needs six Rh+ donors on a certain day. How many people must donate blood to have the probability of obtaining blood from at least six Rh+ donors over 0.95?

With 6 donors:

$P(X = 6) = C_{6,6}.(0.85)^{6}.(0.15)^{0} = 0.3771$

37.71% probability of obtaining blood from at least six Rh+ donors over 0.95.

With 7 donors:

$P(X = 6) = C_{7,6}.(0.85)^{6}.(0.15)^{1} = 0.3960$

0.3771 + 0.3960 = 0.7764 = 77.64% probability of obtaining blood from at least six Rh+ donors over 0.95.

With 8 donors

$P(X = 6) = C_{8,6}.(0.85)^{6}.(0.15)^{2} = 0.2376$

0.3771 + 0.3960 + 0.2376 = 1.01 = 101% probability of obtaining blood from at least six Rh+ donors over 0.95.

There need to be at least 8 people to have the probability of obtaining blood from at least six Rh+ donors over 0.95.

5 0

3 years ago

pls help!! A cylindrical vase has a diameter of 12 inches and a height of 12 inches. If the vase is filled 3/4 full of soil, how

il63 [147K]

Answer:

Answer: the vase contains 1017.36 inches³ of soil.

Step-by-step explanation:

We would apply thee formula for determining the volume of a cylinder which is expressed as

Volume = πr²h

Where

h represents the height of the cylinder

r represents the radius of the cylinder.

π is a constant whose value is 3.14

From the information given

Diameter = 12 inches

Radius = diameter /2 = 12/2

Radius = 6 inches

Height = 12 inches

Therefore,

Volume of the cylindrical vase =

3.14 × 6² × 12 = 1356.48 inches³

If the vase is filled 3/4 full of soil, then the volume of soil in the vase is

3/4 × 1356.48 = 1017.36 inches³

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3 years ago

AXY Zand AABCare similar triangles. Given the dimensions shown in the diagram, what is the

Lady bird [3.3K]

Answer:

3.528

Step-by-step explanation:

First, you need to determine the scale factor. Divide one side in the larger triangle by the corresponding side in the smaller triangle. For example, 8/2. This would give you a scale factor of 2. Then you can reverse the process with the dimensions you need to get the area. The height of the larger triangle is 3.36, so to find the height of the smaller one, you divide it by 2, or the scale factor, to get the height of the smaller triangle which is 1.68. Next, you can solve for area of triangle using a=bh/2, so 4.2*1.68/2=a = 3.528.

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3 years ago

The order of transformations in a sequence matters; reversing the order will not necessarily give the same image. Is this statem

Kamila [148]

Answer:

I think true I'm not sure

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3 years ago

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Svetllana [295]

I really hate these algebra problems pretending to be geometry.