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Kipish [7]
3 years ago
15

A problem on a multiple-choice quiz is answered correctly with probability 0.9 if a student is prepared. An unprepared student g

uesses between 4 possible answers, so the probability of choosing the right answer is 1/4. Seventy-five percent of students prepare for the quiz. If Mr. X gives a correct answer to this problem, what is the chance that he did not prepare for the quiz?
Mathematics
1 answer:
lions [1.4K]3 years ago
3 0

Answer:

0.08475

Step-by-step explanation:

The question above is a application of conditional probability.

The formula to use is Baye's Theorem for conditional probability.

From the above question we have the following information:

Probability of answering correctly when prepared = 0.9

Probability of not answering correctly when prepared = 1 - 0.9 = 0.1

Probability of choosing the right answer = 1/4 = 0.25

Probability of choosing the wrong answer = 1 - 0.25 = 0.75

Number of students that prepare for the quiz = 75% = 0.75

Therefore number of students that did not prepare for the quiz = 1 - 0.75

= 0.25

Hence,

The probability of not preparing but choosing the correct answer =

P[ not prepared | correct answer ]

Is calculated as :

P[ not prepared | correct answer ] =

(0.25 × 0.25)/(0.25 × 0.25) + (0.25 × 0.9)

= 0.08475

Therefore, the chance that Mr X did not prepare for the quiz but he gives the right answer = 0.08475

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Drawing it out would be best can you help me please
leva [86]

Answer:

z_1+z_2 = (-2,5)

Step-by-step explanation:

To Find: z_1+z_2

Solution :

Referring the given graph

We can find the coordinates of   z_1 and  z_2

Coordinates of   z_1= (-7,1)

Coordinates of  z_2= (5,4)

Thus Coordinates of  z_1+z_2 = (-7+5,1+4) = (-2,5)

Thus z_1+z_2 = (-2,5)

So, the point z_1+z_2 = (-2,5) is shown on the attached graph file

6 0
2 years ago
Soap films and bubbles are colorful because the interference conditions depend on the angle of illumination (which we aren't cov
mylen [45]

Answer:

56.39 nm

Step-by-step explanation:

In order to have constructive interference total optical path difference should be an integral number of wavelengths (crest and crest should be interfered). Therefore the constructive interference condition for soap film can be written as,

2t=(m+\frac{1}{2} ).\frac{\lambda}{n}

where λ is the wavelength of light and n is the refractive index of soap film, t is the thickness of the film, and m=0,1,2 ...

Please note that here we include an additional 1/2λ phase shift due to reflection from air-soap interface, because refractive index of latter is higher.

In order to have its longest constructive reflection at the red end (700 nm)

t_1=(m+\frac{1}{2} ).\frac{\lambda}{2.n}\\ \\ t_1=\frac{1}{2} .\frac{700}{(2)*(1.33)}\\ \\ t_1=131.58\ nm

Here we take m=0.

Similarly for the constructive reflection at the blue end (400 nm)

t_2=(m+\frac{1}{2} ).\frac{\lambda}{2.n}\\ \\ t_2=\frac{1}{2} .\frac{400}{(2)*(1.33)}\\ \\ t_2=75.19\ nm

Hence the thickness difference should be

t_1-t_2=131.58-75.19=56.39 \ nm

7 0
2 years ago
Don’t put no links just put a answer now can someone help me
Harlamova29_29 [7]
Nooooooooooooooooooooooooo
4 0
2 years ago
Is my answer correct or no? <br> ---&gt; show explanation &amp; details if i am wrong!!!
neonofarm [45]

Answer:

No, because the distance from the origin to point (7 , -7) is greater than the radius of the circle ⇒ 3rd answer

Step-by-step explanation:

From the graph of the circle

∵ The center of the circle F is at the origin

∴ F is (0 , 0)

∵ The circle passes through point (7 , 0)

- The length of the radius of the circle is the distance between

   the center of the circle and a point on the circle

∴ r is the distance between points (0 , 0) and (7 , 0)

∴ r=\sqrt{(7-0)^{2}+(0-0)^{2}}=\sqrt{49}=7

∴ The length of the radius of the circle is 7 units

Let us find the distance between point (7 , -7) and the origin (0 , 0)

  • If the distance is equal to the radius of the circle, then the point is on the circle
  • If the distance is greater than the radius, then the point is outside the circle
  • If the distance is less than the radius, then the point is inside the circle

∵ The distance =  \sqrt{(7-0)^{2}+(-7-0)^{2}}=\sqrt{49+49}=\sqrt{98}=7\sqrt{2}

∵ r = 7

∵ 7\sqrt{2} > 7

∴ The distance is greater than the radius of the circle

∴ Point (7 , -7) lies outside the circle

The correct answer is:

No, because the distance from the origin to point (7 , -7) is greater than the radius of the circle

<em>Your answer is not correct, the correct answer is the 3rd answer</em>

3 0
3 years ago
Solve the equations and match them with their solutions.
Artyom0805 [142]
1 is x=13.5

2 is x=-260

3 is x=38

4 is x=-37^38

i think this is correct

7 0
3 years ago
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