A multiple-choice examination has 20 questions, each with five possible answers, only one of which is correct. Suppose that one of the students who takes the examination answers each of the questions with an independent random guess. What is the probability that he answers at least seventeen questions correctly? (Round your answer to three decimal places.)

Answer:

c and d

Step-by-step explanation:

the x intercepts are the solutions

Answer:

(0,2) and (-5,0)

Step-by-step explanation:

the point where the two graph lines meet would be the answer.

Answer:

ge

Step-by-step explanation:

ge

Answer:

it it the highest or lowest point of a parabola

Answer:

Step-by-step explanation:

Claim: if the mean amount of garbage per bin is different from 50.

Null hypothesis: u=50

Alternative hypothesis : u =/ 50

Using the z score formular for a one sample z test - z = (x - u ) / (sd/√n)

Where x = 48.99, u = 50 sd =3.7 and n = 36

z = 48.99 - 50 / (3.7/√36)

z = -1.01 / (3.7/6)

z = -1.01/0.6167

z = -1.6377

To find the p value at a 0.01 level of significant from the -1.6377 z score for a two tailed test the p value using the p value calculator is 0.1016. The result is not significant at 0.01 level of significant thus we will fail to reject the null and conclude that the mean amount of garbage per bin is 50.

Answer:

A. y = 7(x + 1)²-3

Step-by-step explanation:

Parabola:

[tex]y = 7x^{2} + 14x + 4[/tex]

[tex]y = 7(x^{2} + 2x) + 4[/tex]

Putting into vertex form, remember that:

[tex](x + a)^{2} = x^{2} + 2ax + a^{2}[/tex]

In this question:

[tex]x^{2} + 2x[/tex], to put into this format:

[tex]x^{2} + 2x + 1 = (x + 1)^{2}[/tex]

We add one inside the parenthesis to do this. The parenthesis is multiplied by 7, so for the equivalent, we also have to subtract 7. Then

Vertex form:

[tex]y = 7(x^{2} + 2x + 1) + 4 - 7[/tex]

[tex]y = 7(x + 1)^{2} - 3[/tex]

So the correct answer is:

A. y = 7(x + 1)²-3

Answer:

27.11% probability that 2 of them have blue eyes

Step-by-step explanation:

For each person, there are only two possible otucomes. Either they have blue eyes, or they do not. The probability of a person having blue eyes is independent of any other person. So we use the binomial probability distribution 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.

8% of all people have blue eyes.

This means that [tex]p = 0.08[/tex]

Random sample of 20 people:

This means that [tex]n = 20[/tex]

What is the probability that 2 of them have blue eyes?

This is P(X = 2).

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

[tex]P(X = 2) = C_{20,2}.(0.08)^{2}.(0.92)^{18} = 0.2711[/tex]

27.11% probability that 2 of them have blue eyes

The probability that 2 of them have blue eyes is 27.11%.

Given that,

Approximately 8% of all people have blue eyes.

Out of a random sample of 20 people,

We have to determine,

What is the probability that 2 of them have blue eyes?

According to the question,

People having blue eyes p = 8% = 0.08

Sample of people n = 20

For each person, there are only two possible outcomes. Either they have blue eyes, or they do not.

The probability of a person having blue eyes is independent of any other person.

The probability that 2 of them have blue eyes is determined by using a binomial probability distribution.

[tex]\rm P (X = x) =n_C_x\times p^x \times (1-p)^{n-x}}[/tex]

Therefore,

The probability that 2 of them have blue eyes is,

[tex]\rm P (X = x) =n_C_x\times p^x \times (1-p)^{n-x}}\\\\ \rm P (X = x) = \dfrac{n!}{(n-x)! \times x!} \times p^x \times (1-p)^{n-x}}\\\\[/tex]

Substitute all the values in the formula,

[tex]\rm P (X = 2) = \dfrac{20!}{(20-2)! \times 2!} \times (0.08)^2 \times (1-0.08)^{20-2}}\\\\ P (X = 2) = \dfrac{20!}{(18)! \times 2!} \times (0.0064) \times (0.92)^{18}}\\\\ P (X = 2) = \dfrac{19\times 20}{ 2} \times (0.0064) \times (0.222)\\\\ P(X = 2) = {19\times 10}\times (0.00142)\\\\P(X = 2) = 0.2711\\\\P(X = 2) = 27.11 \ Percent[/tex]

Hence, The required probability that 2 of them have blue eyes is 27.11%.

For more details refer to the link given below.

https://brainly.com/question/23640563

Answer:

d = 234.6 m

Step-by-step explanation:

You can consider a system of coordinates with its origin at the beginning of the walk of the student.

When she start to walk, she is at (0,0)m. After her first walk, her coordinates are calculated by using the information about the incline and the distance that she traveled:

[tex]x_1=60cos28\°=52.97m\\\\y_1=60sin28\°=28.16m[/tex]

she is at the coordinates (52.97 , 28.16)m.

Next, when she walks 180m to the east, her coordinates are:

(52.97+180 , 28.16)m = (232.97 , 28.16)m

To calculate the distance from the final point of the student to the starting point you use the Pythagoras generalization for the distance between two points:

[tex]d=\sqrt{(x-x_o)^2+(y-y_o)^2}\\\\x=232.97\\\\x_o=0\\\\y=28.16\\\\y_o=0\\\\d=\sqrt{(232.97-0)^2+(28.16-0)^2}m=234.6m[/tex]

The displacement of the student on her complete trajectory was of 234.6m

Answer:

The rental of each chair is $2.75

The rental of each table is $8.5

Step-by-step explanation:

Let's name the unknowns "c" for the cost of each chair rental, and "t" for the cost of each table rental.

Now we can create the equations that represent the statements:

a) "The total cost to rent 2 chairs and 3 tables is $31."

2 c + 3 t = 31

b) "The total cost to rent 6 chairs and 5 tables is $59."

6 c + 5 t = 59

now we have a system of two equations and two unknowns that we proceed to solve via the elimination method by multiplying the first equation we got by "-3" so by adding it term by term to the second equation, we eliminate the variable "c" and solve for "t":

(-3) 2 c + (-3) 3 t = (-3)  31

-6 c - 9 t = -93

6 c + 5 t = 59

both these equations added give:

0 - 4 t = -34

t = 34/4 = 8.5

So each table rental is $8.5

now we find the rental price of a chair by using any of the equations:

2 c + 3 t = 31

2 c + 3 (8.5) = 31

2 c + 25.5 = 31

2 c = 5.5

c = 5.5/2

c = $2.75

Answer:

m = -2/3

Step-by-step explanation:

Slope Formula: [tex]m = \frac{y2-y1}{x2-x1}[/tex]

So,

[tex]m = \frac{-1-1}{9-6}[/tex]

m = -2/3

Answer:

[tex]-4x+28[/tex]

Step-by-step explanation:

[tex]18-2(x+x-5)[/tex]

[tex]18+(-2)(x)+(-2)(x)+(-2)(-5)[/tex]

[tex]18+-2x+-2x+10[/tex]

[tex]-2x-2x+10+18[/tex]

[tex]=-4x+28[/tex]

Answer

its -1

Step-by-step explanation:

ED 2020 boiiiii

The residual value of the line of the best fit when x = 2 is -1

The equation of the line is given as:

y = 0.5x + 1

When x = 2, we have:

y = 0.5 * 2 + 1

Evaluate

y = 2

The residual is the difference between the actual value and the predicted value.

From the complete graph, the actual value is 1.

So, we have:

Residual = 1 - 2

Evaluate

Residual = -1

Hence, the residual value when x = 2 is -1

Read more about residuals at:

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Answer:

Type II error.

Step-by-step explanation:

We have a hypothesis test for the claim that placing a seasonal cookie product on an end cap (the shelf at the end of an aisle at a store) will make a difference in sales.

The null hypothesis will state that there is no difference, while the alternative hypothesis will state that there is significant positive difference.

The result is a P-value of 0.1288 and the null hypothesis failing to be rejected.

As the null hypothesis failed to be rejected, if an error has been made in the conclusion, is that we erroneusly accept a false null hypothesis.

This is a Type II error, where the null hypothesis is accepted although the alternative hypothesis is true.

Answer:

The type of observational study describer here is retrospective study.

Step-by-step explanation:

The complete question is:

Vitamin D is important for the metabolism of calcium and exposure to sunshine is an important source of vitamin D. A researcher wanted to determine whether osteoperosis was associated with a lack of exposure to sunshine. He selected a sample of 250 women with osteoperosis and an equal number of women without osteoperosis. The two groups were matched - in other words they were similar in terms of age, diet, occupation, and exercise levels. Histories on exposure to sunshine over the previous twenty years were obtained for all women. The total number of hours that each woman had been exposed to sunshine in the previous twenty years was estimated. The amount of exposure to sunshine was compared for the two groups. Determine what type of observational study is described. Explain.

Solution:

In retrospective study design, the concerned outcome has previously taken place in each participant by the phase he or she is signed up for the study, and the information are gathered either from past data or by requesting the participants to recall exposures.

It is also known as a historic cohort study.

A retrospective study is completed as posterior experiment, using data on events that have already taken place in the history. In most cases some or most of the data has already been collected and stowed in the archive.

In the provided scenario, the researcher collect the past data for the exposure to sunshine over the previous twenty years for 250 women. And estimated the  total number of hours that each woman had been exposed to sunshine in the previous twenty years.

Then the researcher compares the amount of exposure to sunshine for the two groups.

Thus, the type of observational study describer here is retrospective study.

Answer:

7:1

Step-by-step explanation:

28:4=

7(4):1(4)=

7:1

Hope this helps!

Answer:

[tex]7:1[/tex]

Step-by-step explanation:

[tex]28:4[/tex]

Common highest factor is 4.

Simplify the ratio.

[tex]28 \div 4 : 4 \div 4[/tex]

[tex]7:1[/tex]

Answer:

Step-by-step explanation:

                              Y

p(x,y)            0          1            2

           0      0.10     0.04     0.02

x          1       0.08     0.2     0.06

            2       0.0      0.14     0.30

a) What is P(X = 1 and = 1)

From the table above we have

P(1,1) = 0.2

b)  Compute P(X ≤ 1 and Y ≤ 1).

[tex]=p(0,0)+p(0,1)+p(1,0)+p(1,1)\\\\=0.1+0.04+0.08+0.2\\\\=0.42[/tex]

C)

Let A ={X ≠ 0 and Y ≠ 0}

p{X ≠ 0 , Y ≠ 0}

= p(1,1) + p(1,2) + p(2,1) + p(2,2)

= 0.20 + 0.06 + 0.14 + 0.30

=0.7

d) The possible X values are in the figure 0,1,2

[tex]p_x(0)=p(0,0)+p(0,1)+p(0,2)\\\\=0.1+0.04+0.02\\\\=0.16\\\\p_x(1)=p(1,0)+p(1,1)+p(1,2)\\\\=0.08+0.2+0.06\\\\=0.34\\\\p_x(2)=p(2,0)+p(2,1)+p(2,2)\\\\=0.06+0.14+0.3\\\\=0.5[/tex]

The possible Y values are in the figure 0,1,2

[tex]p_y(0)=p(0,0)+p(1,0)+p(2,0)\\\\=0.1+0.08+0.06\\\\=0.24\\\\p_y(1)=p(0,1)+p(1,1)+p(2,1)\\\\=0.04+0.2+0.14\\\\=0.38\\\\p_y(2)=p(0,2)+p(1,2)+p(2,2)\\\\=0.02+0.06+0.3\\\\=0.38[/tex]

So the probability of x ≤ 1 is

[tex]p(x\leq 1)=p_x(0)+p_x(1)\\\\=0.34+0.16\\\\=0.50[/tex]

e) From the table

[tex]p_x(x=1,y=1)=p(1,1)\\\\=0.2\\\\p_x(1)=0.34\\\\p_y(1)=0.38[/tex]

we multiply both together

0.34  x 0.38

=0.1292

Therefore p(1,1) is not equal px(1), py(1)

Hence x and y are not independent it is not equal

Answer:

Step-by-step explanation:

Add the two equations together:

  (x -y) +(x +y) = (34) +(212)

  2x = 246

  x = 123

  y = x-34 = 89

Malik has 89 foreign stamps and 123 domestic stamps.

Answer:

89 and 123

Step-by-step explanation:

Answer:

1.36364

Step-by-step explanation:

I calculated the solution on a calculator

So the answer to 1 d.p is 1.4

Answer:

y≤4

Step-by-step explanation:

y≤4

try to graph it on a parabola and u will find the answer above :D hope this helped

Answer:

60

Step-by-step explanation:

x=60 .

The triangle is equilateral and x=60 cause the two lines are ||

a. x=60°

b. Alternate interior angles

Solution,

Given,

All sides of triangle are equal.

AB=BC=AC

<ABC=<ACB=<BAC=y

By angle sum property of triangle,

<ABC+<BCA+<CAB=180

or y+y+y=180

or 3y=180

or y=180/3

y=60

Now,

<ACB=<CAD

<CAD(x)=60( Alternate interior angles)

Hope this helps ..

Good luck on your assignment..

Answer:

It is only (5,24).

Step-by-step explanation:

You are correct.

Sometimes, check all options means there could be just one option.

Answer:

x<16

Step-by-step explanation:

number n

eight less than four times a number ... 4 x n - 8

is less than 56 ... < 56

4 x n - 8 < 56

4 x n < 56 + 8

4 x n < 64/4

n < 64 / 4

n < 16

Answer:

Step-by-step explanation:

Let the number be x

Four times the number :  4x

Eight less than four times a number: 4x - 8

4x - 8 < 56

Now add 8 to both sides,

4x < 56+8

4x < 64

Divide both sides by 4,

x < 64/4

x < 16

Possible values of number = Value less than 16

Answer:

670 Cans of fruit will be left

Step-by-step explanation:

First you multiply 155 by the 6 weeks.

That equals 930 and then you subtract 930 from 1,600 and that gives you 670.

There are 670 cans of fruit that will remain after 6 weeks the answer is 670 cans.

It is defined as the systematic way of representing the data that follows a certain rule of arithmetic.

We have:

The local food pantry has 1, 600 cans of fruit. They give away 155 cans of fruit each week.

First term a = 1600

Common difference d = -155

After 6 weeks means on week 7.

n = 7

a(7) = 1600 + (7-1)(-155)

a(7) = 1600 - 930

a(7) = 670

Thus, there are 670 cans of fruit that will remain after 6 weeks the answer is 670 cans.

Learn more about the sequence here:

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Answer:

0.637

Step-by-step explanation:

The average value of a whole sinusoidal waveform over one complete cycle is zero as the two halves cancel each other out

Answer: there are 4 solutions

x = -2

x = -1/2 = -0.500

x =(3-√5)/2= 0.382

x =(3+√5)/2= 2.618

Step-by-step explanation:

Answer:

Triangular Prism

volume 748

Answer:

2.4 hours

Step-by-step explanation:

If Mary is running 26 miles at a pace of 7.5 miles per hour, it will take her 3.47 hours to run the full course.

26/7.5 = 3.466666...

If she has run 8 miles, 1.07 hours have passed.

8/7.5 = 1.06666666...

Subtract the total time from the time that has already passed to find the time left.

3.47 - 1.07 = 2.4

Mary has 2.4 hours left.

Answer:

180

Step-by-step explanation:

2(24)-3=45

24-8=√16=4

45*4=180

Answer:

its 2pi/3

Step-by-step explanation:

because the full radian measure of a circle is 2pi radians, the smaller circle is a third of the size of the larger one. Multiply straight across for (2pi/1)(1/3)  

The circumference of the smaller circle can be given by [tex]\dfrac{2\times \pi}{m}(x)\ units[/tex].

[tex]\rm{Circumference\ of\ the\ circle = 2\times \pi \times (radius)[/tex]

[tex]\rm{Circumference\ of\ the\ circle = 2\times \pi \times (OB)[/tex]

[tex]\rm{Circumference\ of\ the\ circle = 2\times \pi \times (x)[/tex]

Circumference of the Larger circle = 3 x Circumference of the smaller circle

[tex]2\times \pi \times x = 3\times Circumference\ of\ the\ smaller\ circle\\\\3\times Circumference\ of\ the\ smaller\ circle = 2\times \pi \times x \\\\Circumference\ of\ the\ smaller\ circle = \dfrac{2\times \pi \times x }{3}\\\\Circumference\ of\ the\ smaller\ circle = \dfrac{2\times \pi}{3}( x )\ units[/tex]

Hence, the circumference of the smaller circle can be given by [tex]\dfrac{2\times \pi}{m}(x)\ units[/tex].

Learn more about similar circles:

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