Point P' is the image of P(3,5) under a reflection across the y-axis.

Seventy-two percent of the light aircraft that disappear while in flight in a certain country are subsequently discovered. Of th

Anton [14]

Answer:

a) 0.105 = 10.5% probability that it will not be discovered if it has an emergency locator.

b) 0.522 = 52.2% probability that it will be discovered if it does not have an emergency locator.

c) 0.064 = 6.4% probability that 7 of them are discovered.

Step-by-step explanation:

For itens a and b, we use conditional probability.

For item c, we use the binomial distribution along with the conditional probability.

Conditional Probability

We use the conditional probability formula to solve this question. It is

$P(B|A) = \frac{P(A \cap B)}{P(A)}$

In which

P(B|A) is the probability of event B happening, given that A happened.

$P(A \cap B)$ is the probability of both A and B happening.

P(A) is the probability of A happening.

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 combinations 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.

a) If it has an emergency locator, what is the probability that it will not be discovered?

Event A: Has an emergency locator

Event B: Not located.

Probability of having an emergency locator:

66% of 72%(Are discovered).

20% of 100 - 72 = 28%(not discovered). So

$P(A) = 0.66*0.72 + 0.2*0.28 = 0.5312$

Probability of having an emergency locator and not being discovered:

20% of 28%. So

$P(A cap B) = 0.2*0.28 = 0.056$

Probability:

$P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.056}{0.5312} = 0.105$

0.105 = 10.5% probability that it will not be discovered if it has an emergency locator.

b) If it does not have an emergency locator, what is the probability that it will be discovered?

Probability of not having an emergency locator:

0.5312 of having. So

$P(A) = 1 - 0.5312 = 0.4688$

Probability of not having an emergency locator and being discovered:

34% of 72%. So

$P(A \cap B) = 0.34*0.72 = 0.2448$

Probability:

$P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.2448}{0.4688} = 0.522$

0.522 = 52.2% probability that it will be discovered if it does not have an emergency locator.

c) If we consider 10 light aircraft that disappeared in flight with an emergency recorder, what is the probability that 7 of them are discovered?

p is the probability of being discovered with the emergency recorder:

0.5312 probability of having the emergency recorder.

Probability of having the emergency recorder and being located:

66% of 72%. So

$P(A \cap B) = 0.66*0.72 = 0.4752$

Probability of being discovered, given that it has the emergency recorder:

$p = P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.4752}{0.5312} = 0.8946$

This question asks for P(X = 7) when $n = 10$ . So

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

$P(X = 7) = C_{10,7}.(0.8946)^{7}.(0.1054)^{3} = 0.064$

0.064 = 6.4% probability that 7 of them are discovered.

8 0

3 years ago

What is the perimeter of triangle ABC ?

blagie [28]

Answer:

$9+\sqrt{41}$

Step-by-step explanation:

From C-A, it goes from y=1 to y=5, so that 4 units

From A-B, it goes from x = -1 to x = 4, that is 5 units

Now, to find distance from B to C, we need to use the distance formula:

$D=\sqrt{(y_2-y_1)^2+(x_2-x_1)^2}$

Where the variables are the respective points of B and C,

B (4,5) & C(-1,1)

So x_1 =4, y_1=5, x_2=-1, y_2=1

Plugging into the formula we get:

$D=\sqrt{(y_2-y_1)^2+(x_2-x_1)^2}\\D=\sqrt{(1-5)^2+(-1-4)^2}\\D=\sqrt{16+25}\\ D=\sqrt{41}$

Summing it all (perimeter is sum of 3 sides):

Distance = $4+5+\sqrt{41}\\ =9+\sqrt{41}$

3rd answer choice is right.

3 0

3 years ago

PLLLLSSS HELP ME ASAP!

erastovalidia [21]

The answer to the first one is ' D '.
(All the angles inside a triangle have to add up to exactly 180 degrees.)

The answer to the second one is ' C ' .
(If two sides are equal, then the sides opposite them are also equal.)

3 0

3 years ago

NEED ASAP!!!

k0ka [10]

Answer:

N = 3

Step-by-step explanation:

If 6 = 1 and n = 1/2 then n is 1/2 of 6

6/2 = 3

4 0

3 years ago

.<br> Which could be a value for n?

snow_lady [41]

Answer:

A. $-\frac{1}{2}$

Step-by-step explanation:

Each mark represent 0.1 unit, so if you count from 0 to $n$ you get 0.5 that is exactly the same that $-\frac{1}{2}$ (for convention the left of the 0 is taken as negative and the right as positive).

7 0

2 years ago