A quiz consists of six multiple choice questions. Each question has four choices. A student who forgot to study guesses randomly on every question. What is the probability that the student answers at most four questions correctly?

Answers

Answer 1

Answer:

0.9945 = 99.45% probability that the student answers at most four questions correctly

Step-by-step explanation:

For each question, there are only two possible outcomes. Either the student answers correctly, or he/she does not. The probability of the student answering a question correctly is independent of any other question. This means that the binomial probability distribution is used to solve this question.

Binomial probability distribution

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

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And p is the probability of X happening.

A quiz consists of six multiple choice questions.

This means that [tex]n = 6[/tex]

Each question has four choices. Student guesses randomly.

This means that [tex]p = \frac{1}{4}[/tex]

What is the probability that the student answers at most four questions correctly?

This is:

[tex]P(X \leq 4) = 1 - P(X > 4)[/tex]

In which

[tex]P(X > 4) = P(X = 5) + P(X = 6)[/tex]. So

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 5) = C_{6,5}.(0.25)^{5}.(0.75)^{1} = 0.0053[/tex]

[tex]P(X = 6) = C_{6,6}.(0.25)^{6}.(0.75)^{0} = 0.0002[/tex]

[tex]P(X > 4) = P(X = 5) + P(X = 6) = 0.0053 + 0.0002 = 0.0055[/tex]

[tex]P(X \leq 4) = 1 - P(X > 4) = 1 - 0.0055 = 0.9945[/tex]

0.9945 = 99.45% probability that the student answers at most four questions correctly


Related Questions

guys help me
can u give me the answer ​

Answers

Answer:

A factor, in mathematics, a number or algebraic expression that divides another number or expression evenly, with no remainder. A multiple of a number is any integer multiplied by the number. Try it yourself, now you know the how it works.

Bert measured a swimming pool and made a scale drawing. The scale of the drawing was
1 centimeter = 1 meter. What scale factor does the drawing use?
Simplify your answer and write it as a fraction.
Submit

Answers

1/100
Each meter is 100 centimeter

Trying to finish this test at 3:30 am plz help

Answers

Given:

The given sum is:

[tex]\sum _{k=4}^9(5k+3)[/tex]

To find:

The expanded form and find the sum.

Solution:

We have,

[tex]\sum _{k=4}^9(5k+3)[/tex]

The expanded form of given sum is:

[tex]\sum _{k=4}^9(5k+3)=(5(4)+3)+(5(5)+3)+(5(6)+3)+(5(7)+3)+(5(8)+3)+(5(9)+3)[/tex]

[tex]\sum _{k=4}^9(5k+3)=(20+3)+(25+3)+(30+3)+(35+3)+(4+3)+(45+3)[/tex]

[tex]\sum _{k=4}^9(5k+3)=23+28+33+38+43+48[/tex]

[tex]\sum _{k=4}^9(5k+3)=213[/tex]

Therefore, the correct option is C.

Work out cube root of 512 : reciprocal of 0.4. Give your answer in the form n : 1

Answers

Step-by-step explanation:

Thanks, so cube root of 512 is 8 and reciprocal of 0.4 is 2.5 then:

8 : 2.5 / divide both by 2.5 to get:

3.2 : 1 that's my answer right?

The correct form of the ratio of cube root of 512: reciprocal of 0.4 is 3.2:1

What is a cube root?

It is a number y such that y to the power 3 is equal to x.

How to find ratio?

We have to find the ratio of cube root of 512 and the reciprocal of 0.4  which will be as follows

cube root of 512:  reciprocal of 0.4

8: 1/0.4

8=2.5

dividing by 2.5

3.2 : 1

Hence the ratio will be 3.2 :1 of cube root of 512 and the reciprocal of 0.4

Learn more about cube root at https://brainly.com/question/310302

#SPJ2

A section of a deck is shaped like a trapezoid. For this section, the length of one base is 41 feet, and the length of the other base is 36 feet. The height is 20 feet. What is the area of this section of the deck?

Answers

Answer:

Step-by-step explanation:

The area of the outer rectangle above is 80 ft, and the area of the inner rectangle is 68 ft. What is the area of the shaded region?

Answers

Answer:

B

Step-by-step explanation:

is the right answer

The area of the shaded region is 12 feet². The correct option is A.

What is a rectangle?

A rectangle is a type of quadrilateral that has its parallel sides equal to each other and all the four vertices are equal to 90 degrees.

Given that the area of the outer rectangle above is 80feet². The area of the inner rectangle is 68feet². The area of the shaded region=area of the outer rectangle- the area of the inner rectangle.

The area of the shaded region=(80-68 )feet²

The area of the shaded region= 12feet²

Thus,  the area of the shaded region is 12feet².

Learn more about rectangles here:

https://brainly.com/question/23515075

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Please help me solve this problem

Answers

Answer:

90°

Step-by-step explanation:

It's simple, the angle of a line is 180°

∠EFG=90°

Line GD-∠EFG=180°-90°=90°

Please mark brainliest!

James drove 29 hours at a rate of 65 mph. How many miles did he drive?

Answers

James drove 1,885 miles.

Help please
(Worth 10 points)
Please respond with a actual answer
*No robots no bad links*

Answers

The dude typing gonna help u

A consumer group claims that the average annual consumption of high fructose corn syrup by a person in the U.S. is 48.8 pounds. You believe it is higher. You take a simple random sample of 35 people in the U.S. and find an average of 53.8 pounds with a standard deviation of 4.4 pounds. Test at 1% significance. Round to the fourth

Answers

Answer:

[tex]6.7159[/tex]

Step-by-step explanation:

[tex]\mu=48.8\\n=35\\\bar{x}=53.8\\\sigma=4.4\\\alpha=1\%=0.01[/tex]

Null and alternative hypothesis :

[tex]H_0:\mu=48.8\\H_a:\mu>48.8[/tex]

Test statistic,

[tex]t=\frac{\bar{x}-\mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

[tex]\Rightarrow t=\frac{53.8-48.8}{\frac{4.4}{\sqrt{35}}}[/tex]

[tex]\Rightarrow t=\frac{5\times 5.91}{4.4}[/tex]

[tex]\Rightarrow t=6.715[/tex]

Test statistic [tex]t=6.715[/tex]

[tex]P-[/tex]value [tex]=P(t>6.715)[/tex]

[tex]P-[/tex] value [tex]=0.0001[/tex]  by the p- table

Significance level [tex]0.01[/tex]

         [tex]p-[/tex]value [tex]<0.01[/tex]

  We reject [tex]H_0[/tex]

If f(x)=2x^2+5 square root (x-2) what does f(3)=?

Answers

Answer:

f(3) = 23

Step-by-step explanation:

It equals 23!! Hope it helps

Could you please explain in detail how to graph this. Thank you:)

Answers

just divide and that it

Five friends are sharing 4 fruit bars. Each friend gets the same amount.
How much fruit bar does each friend get?

Answers

Answer:

4/5 of a fruit bar

Step-by-step explanation:

I need the answer fast pls

Answers

Answer:

C. 15

Step-by-step explanation:

You just need to add the number of dots, hoped this helped and was fast enough

A study was conducted on students from a particular high school over the last 8 years. The following information was found regarding standardized tests used for college admitance. Scores on the SAT test are normally distributed with a mean of 1070 and a standard deviation of 204. Scores on the ACT test are normally distributed with a mean of 19.1 and a standard deviation of 5.2. It is assumed that the two tests measure the same aptitude, but use different scales.
(A) If a student gets an SAT score that is the 51-percentile, find the actual SAT score. Round answer to a whole number. SAT score =
(B) What would be the equivalent ACT score for this student? Round answer to 1 decimal place. ACT score =
(C) If a student gets an SAT score of 1417, find the equivalent ACT score. Round answer to 1 decimal place. ACT score =

Answers

Answer:

a) SAT score = 1075

b) ACT score = 19.2.

c) ACT score = 27.9.

Step-by-step explanation:

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

(A) If a student gets an SAT score that is the 51-percentile, find the actual SAT score

SAT scores have mean 1070 and standard deviation 204, so [tex]\mu = 1070, \sigma = 204[/tex]

51th percentile means that Z has a p-value of 0.51, so Z = 0.025. The score is X. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]0.025 = \frac{X - 1070}{204}[/tex]

[tex]X - 1070 = 0.025*204[/tex]

[tex]X = 1075[/tex]

SAT score = 1075.

(B) What would be the equivalent ACT score for this student?

ACT scores have mean of 19.1 and standard deviation of 5.2, which means that [tex]\mu = 19.1, \sigma = 5.2[/tex]. The equivalent score is X when Z = 0.025. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]0.025 = \frac{X - 19.1}{5.2}[/tex]

[tex]X - 19.1 = 0.025*5.2[/tex]

[tex]X = 19.2[/tex]

ACT score = 19.2.

(C) If a student gets an SAT score of 1417, find the equivalent ACT score.

Z-score for the SAT:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{1417 - 1070}{204}[/tex]

[tex]Z = 1.7[/tex]

Equivalent score on the ACT:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]1.7 = \frac{X - 19.1}{5.2}[/tex]

[tex]X - 19.1 = 1.7*5.2[/tex]

[tex]X = 27.9[/tex]

ACT score = 27.9.

I need help with all 4 questions plz

Answers

2x is the highest common factor of the expression

what time is seven to eight

Answers

The time between 7 to 8 is one hour if that’s what you’re asking for

I need help, please !

Answers

Answer: the answer is 8 because

Step-by-step explanation:

Use the Law of Cosines to find the measure of ∠A. Round to the nearest degree.

a = 12, b = 5, c = 9

Use: a² = b² + c² – 2bc cos A

Answers

Answer:

Solution given:

a = 12, b = 5, c = 9

We have

: a² = b² + c² – 2bc cos A

12²=5²+9²-2×5×9 cos A

12²-25-81=-90 cos A

cos A=38/-90

A=cos -1(-19/45)

A=115°

is a required answer.

will give brainliest

Answers

Answer:

Step-by-step explanation:

1/48 + 5/6    

The LCD of 48 and 6 is 48 so we have:

1/48 + 40/48

= 41/38

Answer:

41/48

Step-by-step explanation:

The following two-way table describes student's
after school activities. Find the probability that a
randomly selected student works, given that it's a
senior.
Grade
Sports
Music/Drama
Work
Sophomore
20
7
3
Junior
20
13
2
Senior
25
5
5
P( Work | Senior) = [?]
Round to the nearest hundredth.

Answers

Answer:

[tex]P(Work | Senior) = 0.14[/tex]

Step-by-step explanation:

Given

The attached table

Required

[tex]P(Work | Senior)[/tex]

This is calculated using:

[tex]P(Work | Senior) = \frac{P(Work \ n\ Senior)}{P(Senior)}[/tex]

This gives:

[tex]P(Work | Senior) = \frac{n(Work \ n\ Senior)}{n(Senior)}[/tex]

From the table:

[tex]n(Work \ n\ Senior) = 5[/tex]

[tex]n(Senior) = 25 + 5+ 5 = 35[/tex]

So:

[tex]P(Work | Senior) = \frac{5}{35}[/tex]

[tex]P(Work | Senior) = 0.14[/tex]

Answer:

14%

Step-by-step explanation:

add 25+5+5 (because that is all the numbers in the 'Seniors' row) and then take the 5 that is in the 'Work' column and put that over 25. (5/25 fraction as a percent is 14).

Find a polynomial equation that has roots of -2 and double root 3

Answers

Answer:

x³ + 2x² -3x +6

Step-by-step explanation:

We need to find the polynomial whose roots are ,

-2 , √3 and √3.

Say of we have zeroes as , α , β and γ , then the polynomial is ,

=> p(x) = k[ (x - α ) ( x - β) ( x - γ) ]

where k is constant. Substituting the respective values , we have ,

=> p(x) = k [ ( x - (-2)) ( x - √3) ( x -√3)]

=> p(x) = k[ (x+2)(x² - 3)]

=> p(x) = k[ x(x² - 3) + 2(x² - 3) ]

=> p(x) = k[ x³ - 3x + 2x² - 6 ]

=> p(x) = k[ + 2x² - 3x - 6 ]

Hence the cubic polynomial is + 2x² - 3x + 6 .

Ashley started washing at 10:28 AM and finished at 10:41 AM.
How long did it take her? Give your answer in minutes.

Answers

Answer:

13 minutes

Step-by-step explanation:

The reason why it is 13 minutes is because you subtract 10:41 AM from 10:28 AM and you get 13 minutes.

Answer:

13

Step-by-step explanation:

41-28= 13

the hours don't change so you just need to subtract the minutes

A square has an area of 196 square centimeters. What is the length of each side?

Answers

Answer:

The answer is simply 49.

Step-by-step explanation:

196 ÷ 4 is why because their are 4 sides on a square if you divide it by 4 you get the answer 49. You're probably in like 3rd grade or smth this is so easy.

Chile I’m struggling

Answers

Answer:

the answer is c

Step-by-step explanation:

Please help me solve this

Answers

9514 1404 393

Answer:

  103°

Step-by-step explanation:

The law of sines tells you ...

  sin(C)/c = sin(A)/a

  sin(C) = (c/a)sin(A)

  C = arcsin(c/a·sin(A)) = arcsin(37/19·sin(30°)) ≈ 180° -76.8° ≈ 103°

Obtuse angle C is about 103°.

A vector is used to express a car's change in position, or displacement, by tracking its motion over a large area defined by a coordinate grid. If the car begins at (−3,−5) and ends at (5,9), which of these expresses the car's displacement in vector form?

A
(14,8)

B
(10,12)

C
(8,14)

D
(2,4)

Answers

Answer:

The correct answer is option C: (8, 14).

Step-by-step explanation:

The car's displacement in vector form can be found by subtracting the initial points from the final points.    

Initial: (x₁, y₁) = (-3, -5)

Final: (x₂, y₂) = (5, 9)          

For the x-coordinate, we have:  

[tex] d_{x} = x_{2} - x_{1} = 5 - (-3) = 8 [/tex]

And for the y-coordinate, we have:

[tex] d_{y} = y_{2} - y_{1} = 9 - (-5) = 14 [/tex]

The car's displacement in vector form is:

[tex] d = (d_{x}, d_{y}) = (8, 14) [/tex]  

Therefore, the correct answer is option C: (8, 14).

I hope it helps you!                        

Three years ago the sum of the ages of father and his son was
48 years and three years hence father's age will be three times
that of his son. Find the present ages of the father and his son.​

Answers

Answer:

The father is 42 years old and the son is 12 years old.

Step-by-step explanation:

Since three years ago the sum of the ages of father and his son was 48 years, and three years hence father's age will be three times that of his are his, to find the present ages of the father and his are his, the following calculations must be performed:

F + S = 48

F + 6 + S + 6 = 3S

34 + 14 = 48 /// 34 + 6 = 40 --- 14 + 6 = 20 (x 3 = 60)

38 + 10 = 48 /// 38 + 6 = 44 --- 10 + 6 = 16 (x 3 = 48)

40 + 8 = 48 /// 40 + 6 = 46 --- 8 + 6 = 14 (x 3 = 42)

39 + 9 = 48 /// 39 + 6 = 45 --- 9 + 6 = 15 (x 3 = 45)

39 + 3 = 42

9 + 3 = 12

Therefore, the father is 42 years old and the son is 12 years old.

What choice is the range of f(x)=√x-3-1

Answers

Answer:

its not loading

Step-by-step explanation:

Tammy has scored 82, 78, and 93 on her previous three tests. What score does she need on her next test so that her average (mean) is 81?

Answers

Answer:

She needs a grade of 71 on her next text.

Step-by-step explanation:

Mean of a data-set:

The mean of a data-set is the sum of all values in the data-set divided by the number of values.

Tammy has scored 82, 78, and 93 on her previous three tests.

Thus, her grades are 82, 78, 93 and x, in which x is her grade in the fourth test.

There are 4 tests.

What score does she need on her next test so that her average (mean) is 81?

We have to find x when the mean is 81. So

[tex]\frac{82 + 78 + 93 + x}{4} = 81[/tex]

[tex]253 + x = 324[/tex]

[tex]x = 324 - 253[/tex]

[tex]x = 71[/tex]

She needs a grade of 71 on her next text.

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