What is the constant proportionality of $0.59 per pound

The probability that a single radar station will detect an enemy plane is 0.65.

taurus [48]

Answer:

a) We need 4 stations to be 98% certain that an enemy plane flying over will be detected by at least one station.

b) If seven stations are in use, the expected number of stations that will detect an enemy plane is 4.55.

Step-by-step explanation:

For each station, there are two two possible outcomes. Either they detected the enemy plane, or they do not. This means that we can solve this problem using concepts of the binomial probability distribution.

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:

The probability that a single radar station will detect an enemy plane is 0.65. This means that $n = 0.65$ .

(a) How many such stations are required to be 98% certain that an enemy plane flying over will be detected by at least one station?

This is the value of n for which $P(X = 0) \leq 0.02$ .

n = 1.

$P(X = 0) = C_{1,0}.(0.65)^{0}.(0.35)^{1} = 0.35$

n = 2

$P(X = 0) = C_{2,0}.(0.65)^{0}.(0.35)^{2} = 0.1225$

n = 3

$P(X = 0) = C_{3,0}.(0.65)^{0}.(0.35)^{3} = 0.0429$

n = 4

$P(X = 0) = C_{4,0}.(0.65)^{0}.(0.35)^{4} = 0.015$

We need 4 stations to be 98% certain that an enemy plane flying over will be detected by at least one station.

(b) If seven stations are in use, what is the expected number of stations that will detect an enemy plane?

The expected number of sucesses of a binomial variable is given by:

$E(x) = np$

So when $n = 7$

$E(x) = 7*(0.65) = 4.55$

If seven stations are in use, the expected number of stations that will detect an enemy plane is 4.55.

6 0

2 years ago

If the measure of angle BCD=51 degrees, solve for x.

BabaBlast [244]

Answer:

$x=5$

Step-by-step explanation:

step 1

Find the measure of angle EFD

In this problem I will assume that ABCD is a parallelogram

In a parallelogram opposite angles are congruent and consecutive angles are supplementary

so

$m\ angle BCD=m\angle BED=51^o$

$m\ angle FED=(1/2)m\angle BED=(1/2)51^o=25.5^o$ --- > given problem

Remember that the sum of the interior angles in any triangle must be equal to 180 degrees

so

In the triangle EFD

$m\ angle FED+m\ angle FDE+m\ angle EFD=180^o$

substitute the given values

$25.5^o+55^o+m\ angle EFD=180^o$

$80.5^o+m\ angle EFD=180^o$

$m\ angle EFD=180^o-80.5^o$

$m\ angle EFD=99.5^o$

step 2

Find the measure of angle EFB

we know that

$m\angle EFB+m\angle EFD=180^o$ ---> by supplementary angles

we have

$m\ angle EFD=99.5^o$

substitute

$m\angle EFB+99.5^o=180^o$

$m\angle EFB=180^o-99.5^o$

$m\angle EFB=80.5^o$

step 3

Find the value of x

Remember that the sum of the interior angles in any triangle must be equal to 180 degrees

so

In the triangle EBF

$m\ angle BEF+m\ angle EFB+m\ angle EBF=180^o$

we have

$m\angle BEF=m\ angle FED=25.5^o$

$m\angle EFB=80.5^o$

$m\angle EBF=(14x+4)^o$

substitute

$25.5^o+80.5^o+(14x+4)^o=180^o$

solve for x

Combine like terms

$(14x+110)^o=180^o$

$14x=180-110$

$14x=70$

$x=5$

4 0

3 years ago

As part of the quality-control program for a catalyst manufacturing line, the raw materials (alumina and a binder) are tested fo

denis-greek [22]

Hi how was your day today Mr. person

6 0

2 years ago

What is the volume of the cone with a height of 3ft and a radius of 4 ft in cubic ft

tino4ka555 [31]

The answer is 50.24 ft

4 0

3 years ago

The average of three numbers is 25. The average of two of those numbers is 21. What is the value of the third number of the orig

Elza [17]

Answer:

b) 33

Step-by-step explanation:

You reverse the process of finding the second average, 21, which will help you find the original average, 25. First you multiply the second average, 21, to retrace your steps. We do this because the last thing we do when we find the average is divide. when you multiply 21 you get 42. Now you have the value of the first two numbers. Then you experiment with the numbers. To save time I'll get to the point. When you add 33 + 42 you get 75. Then you divide by 3 to get 25. You divide by three because the instructions say there was 3 numbers to start with. Hope this helps.

8 0

3 years ago

What is the constant proportionality of $0.59 per pound​

What is the constant proportionality of $0.59 per pound