Please help I don't understand ​

Answer:

Step-by-step explanation:

[tex]10C_{7}\times (0.2)^{7} \times (0.8)^{3}\\[/tex]

The probability that a student guesses the correct answer to exactly 7 questions is 0.004.

The probability of exactly x successes on n repeated trials in an experiment which has two possible outcomes is called binomial probability.

[tex]P_{x} =nC_{x} P^{x} q^{n-x}[/tex]

where,

P is binomial probability

x is number of times for a specific outcome within n trials

[tex]nC_{x}[/tex] number of combinations

p is probability of success on a single trial

q is probability of failure on a single trial

n is number of trials

According to the given question.

A test consisted of 10 multiple choices.

⇒ Number of trials,  n = 10

The student have to give exactly 7 correct answers.

⇒ x = 7

The probability of being correct in one trial, p = [tex]\frac{1}{5}[/tex]    

(only one option is correct among fives)

So, the probability of being incorrect/wrong in one trial, q = [tex]1-\frac{1}{5} =\frac{4}{5}[/tex]

Therefore, the probability that a student guesses the correct answer to exactly 7 questions is given by

[tex]P_{x} = 10C_{7} (\frac{1}{5}) ^{7} (\frac{4}{5} )^{3}[/tex]

⇒ [tex]P_{x} = \frac{10!}{7!3!} (0.2)^{7}( 0.8)^{3}[/tex]

⇒[tex]P_{x} = 120(0.0000128)(0.512)[/tex]

⇒ [tex]P_{x} =0.004[/tex]

Hence, the probability that a student guesses the correct answer to exactly 7 questions is 0.004.

Find out more information about binomial probability here:

https://brainly.com/question/12474772

#SPJ3

Answer:

I need points

Step-by-step explanation:

Answer:

Proved

Step-by-step explanation:

Given

[tex]n = 6[/tex] --- sides of hexagon

[tex]l = 1[/tex] --- side length

Required

Prove that for 7 points picked from the interior, 2 points are at most 1 unit apart

1. Draw a hexagon  (see attachment)

2. Divide the hexagon into 6 triangles

3. Select 7 points on the hexagon

You will notice that at least 2 points will be in one of the triangle.

The maximum distance between these two points is 1 unit. This is because

1. The triangle is equilateral (all sides equal)

2. The length of each is 1 unit (in other words, the distance between points, cannot exceed the side length)

Answer:

8

Step-by-step explanation:

40÷5=8

Hope this helps! :)

Answer:

3:6:9

Step-by-step explanation:

1/1+2+3 × 90 = 15

2/1+2+3 × 90 = 30

3/1+2+3 × 90 = 45

9514 1404 393

Explanation:

In a cyclic quadrilateral, opposite angles are supplementary. This means ...

  A + C = 180°   ⇒   A/2 +C/2 = 90°   ⇒   C/2 = 90° -A/2

  B + D = 180°   ⇒   B/2 +D/2 = 90°   ⇒   D/2 = 90° -B/2

It is a trig identity that ...

  tan(α) = cot(90° -α)

so we have ...

  tan(A/2) = cot(90° -A/2) = cot(C/2)

and

  tan(B/2) = cot(90° -B/2) = cot(D/2)

Adding these two equations together gives the desired result:

  tan(A/2) +tan(B/2) = cot(C/2) +cot(D/2)

Answer:

D. its the only straight line

Step-by-step explanation:

by the way, they are all functions

Answer:

3 : 7

Step-by-step explanation:

The ratio of girls to boys = 4 : 3

Since there are only two possible genders :

Then the total fraction of student is the sum of the ratio = (4 + 3)

Since,

Boys = 3

The ratio of boys to the total number of student in the class will be :

Boys : Total

3 : 7

9514 1404 393

Answer:

  acute

Step-by-step explanation:

The third angle is ...

  180° -49° -82° = 49°

So, the triangle has two angles the same, 49°. When two angle are the same, the triangle is an isosceles triangle.

The largest angle, 82°, is less than 90°, so is an acute angle. The classification acute, right, or obtuse is based on the measure of the largest angle.

The triangle is an acute isosceles triangle.

Answer:

C.

Step-by-step explanation:

When you replace x with x - h, the graph shifts h units horizontally.

Here, x is replaced by x - 12.

Compare x - 12 to x - h.

h = 12

The graph shifts 12 units to the right.

Answer:

answer maybe A..not sure but it might be in my opinion..

Answer:

The area is 105.5ft^2

Step-by-step explanation:

Required

The area of the composite figure

The figure can be divided to 2 shapes

(1) Rectangle: Length = 6ft and Width = 8ft

(2) Trapezoid: Height = 5ft (i.e. 8 - 3), Parallel sides = 9ft and 14ft (i.e. 20 - 6)

The area of the rectangle is:

[tex]Area = 6 * 8 = 48[/tex]

The area of the trapezoid is:

[tex]Area = \frac{1}{2}(9 + 14) * 5[/tex]

[tex]Area = \frac{1}{2}(23) * 5[/tex]

[tex]Area = 11.5 * 5[/tex]

[tex]Area = 57.5[/tex]

So, the area of the garden is:

[tex]Total = 48 + 57.5[/tex]

[tex]Total = 105.5[/tex]

Answer:

1. A. Quantitative data

B. Quantitative data

C. Qualitative data

D. Quantitative data

E. Qualitative data

F. Quantitative data

2.a. Yearly salaries: interval or ratio data

b. Employee numbers: interval or ratio data

c. Area codes : nominal data

d. The ages: interval or ratio data

e. Survey answers: ordinal data

f. IQ index: interval or ratio data

Explanation:

Qualitative data is data in the form of a quality such as a characteristic. It is usually a noun, such as whether a person is fair or dark in complexion. Quantitative data is data in form of quantity such as the amount in dollars of one's salary.

There are four levels of data measurement. They are: nominal data, ordinal data, interval data, and ratio data. Nominal and ordinal data are qualitative data while interval and ratio data are quantitative data.

Answer:

[tex]A=379.94\ m^2[/tex]

Step-by-step explanation:

Given that,

The radius of a circl is 11 m

We need to find the area of the circle. The forcemula for the area of a crcle is given by :

[tex]A=\pi r^2[/tex]

Put all the values,

[tex]A=3.14\cdot11^{2}\\A= 379.94\ m^2[/tex]

So, the area of the circle is equal to [tex]379.94\ m^2[/tex].

Answer:94.985 m 2

Step-by-step explanation:

Answer:

x=5

y=0

Step-by-step explanation:

KL = JM

3x-y = 15

and JK = LM

4x -4y = 20

Divide this equation by 4

x-y= 5

Multiply by -1

-x+y =-5

Add this to the first equation

3x-y = 15

-x+y =-5

-----------------

2x = 10

Divide by 2

2x/2 = 10/2

x =5

x-y = 5

5-y = 5

-y = 0

y =0

Answer:

x=5,y=0

Step-by-step explanation:

KL=JM [Opposite sides of rectangle are equal]

3x-y=15-> eq 1

JK=LM

4x-4y=20

=>4(x-y)=20

=>x-y=5-> eq 2

From eq 1 and 2,

   3x-y=15

     x-y=5

=>2x=10

=>x=5

x-y=5

y=x-5

=>y=5-5

=>y=0

Using the dot plot, it is found that a typical amount of chocolate chips in one of Shawn's cookies is around 4.56.

The dot plot is a graph shows the number of times each measure appears in the data-set.

Researching this problem on the internet, the dot plot states that:

The mean is given by:

M = (2 x 2 + 2 x 3 + 5 x 4 + 4 x 5 + 3 x 6 + 2 x 7)/(2 + 2 + 5 + 4 + 3 + 2) = 4.56.

Hence, a typical amount of chocolate chips in one of Shawn's cookies is around 4.56.

More can be learned about dot plots at https://brainly.com/question/24912483

Answer:

5 chocolate chips

Step-by-step explanation:

did on khan

Answer:

47

Step-by-step explanation:

Answer:

hi, the answer is 47°

Step-by-step explanation:

68+135+110=313 360-313=47

Answer:

[tex]13[/tex]

Step-by-step explanation:

Donna's Rate is [tex]R[/tex]

Rico's Rate is [tex]R+2[/tex]

[tex]\frac{R}{R+2}=\frac{2}{3}[/tex]

Cross-Multiply

[tex]2(R+2)=32[/tex]

[tex]2R+4=3R[/tex]

[tex]4=R[/tex]

Donna's Rate is [tex]R=4[/tex]

Rico's Rate is [tex]R+2=6[/tex]

[tex]\frac{6(130)}{60} = \frac{130}{10}=13[/tex]

9514 1404 393

Answer:

  A.  y = 3^-x +1

Step-by-step explanation:

Reflection across the y-axis replaces x with -x. The reflected curve is described by ...

  y = 3^-x +1 . . . . matches choice A

Answer:

£8520

Step-by-step explanation:

1 Bahraini dinar = £2.13

Multiply both sides of the equation by 4000.

4000 * 1 Bahraini dinar = 4000 * £2.13

4000 Bahraini dinar = £8520

I'll focus on problem 2.

For these types of problems, I recommend graphing the functions to see how the end behavior looks.

The graph of y = x^2 has a parabola where both endpoints aim upward. So each end goes to positive infinity (regardless if x is going to positive or negative infinity).

In short, the graph rises to the left and it rises to the right.

Increasing the leading coefficient will not change this fact. We can pick any leading coefficient we want and the end behavior will stay the same. All that matters is the leading coefficient is positive.

If the leading coefficient becomes negative, then everything flips: the endpoints will aim down. The other terms we add on (such as a 3x+3) will not change the end behavior. The leading term, with the largest exponent, is what directly and solely determines the end behavior.

The graph is shown below. I used GeoGebra to make the graph. Desmos is another handy tool you could use.

Answer:

[tex]x_1 = -t[/tex]

[tex]x_2 = s[/tex]

[tex]x_3 = 0[/tex]

[tex]x_4 = t[/tex]

Step-by-step explanation:

Given

[tex]\left[\begin{array}{cccc}1&0&0&1\\0&0&1&0\\0&0&0&0\end{array}\right][/tex]

Required

Determine x1 to x4

First, we write the augmented matrix

[tex]\left[\begin{array}{cccc}1&0&0&1\\0&0&1&0\\0&0&0&0\end{array}\right] = \left[\begin{array}{c}0&0&0\end{array}\right][/tex]

Taking the position of each column, we have:

[tex]x_1 + 0 + 0 +x_4 = 0[/tex]

[tex]0 + 0 + x_3 +0 = 0[/tex]

[tex]0 + 0 + 0 + 0 = 0[/tex]

There is no explicit equation for [tex]x_2[/tex]

So: [tex]x_2 = s[/tex] ----- arbitrary variable

[tex]x_1 + 0 + 0 +x_4 = 0[/tex] implies that:

[tex]x_1 + x_4 = 0[/tex]

[tex]0 + 0 + x_3 +0 = 0[/tex] implies that

[tex]x_3 = 0[/tex]

[tex]0 + 0 + 0 + 0 = 0[/tex] implies that

[tex]0 = 0[/tex]

So, we have:

[tex]x_1 + x_4 = 0[/tex]

[tex]x_3 = 0[/tex]

[tex]x_1 + x_4 = 0[/tex] becomes

[tex]x_1 = -x_4[/tex]

Let

[tex]x_4 = t[/tex]

So:

[tex]x_1 = -x_4[/tex]

[tex]x_1 = -t[/tex]

Where t , s are real numbers

Answer:

8x + 2y + 250 grams

Step-by-step explanation:

The box contains

8 text   books each with a mass of x grams = 8x

2 dictionaries each with a mass of  y grams = 2y

1 box                                                                 = 250 grams

Total                                                                 = 8x + 2y + 250

Answer:

HK = 24

Step-by-step explanation:

HK and JL are diagonals of the parallelogram.

Recall that diagonals of a parallelogram bisect each other. This implies that, they divide each other into equal parts.

Therefore,

HK = 2(HM)

HM = 12

Thus,

HK = 2(12)

HK = 24

Answer:

Step-by-step explanation:

The natural logarithm of x is generally written as ln x, loge x, or sometimes, if the base e is implicit, simply log x.

Answer:

Ln x as opposed to log x

Step-by-step explanation:

Answer: 10 in

Step-by-step explanation:

Answer:

315 in²

Step-by-step explanation:

the surface area is the sum of the areas of all the individual shapes in the surface.

so, we have the 2 triangular bases and 3 rectangles as is sides.

the area of a rectangular triangle is a×b/2

we need them twice, so that is then a×b

a=4.5

b=6

a×b = 27 in²

one rectangle is 16×7.5 = 120 in²

one rectangle is 16×6 = 96 in²

one rectangle is 16×4.5 = 72 in²

total surface area is therefore

A = 27+120+96+72 = 315 in²

Answer:

Equation: [tex](x-2)^2=16(y-2)[/tex]

Vertex: [tex](2,2)[/tex]

Directrix: [tex]y=-2[/tex]

Focus: [tex](2,6)[/tex]

Step-by-step explanation:

Standard Form of Vertical Parabola:

We know that our vertex is [tex](h,k)[/tex] -> [tex](2,2)[/tex], therefore, we can determine the value of [tex]p[/tex] by selecting a point from the parabola as [tex](x,y)[/tex]:

[tex](x-h)^2=4p(y-k)[/tex]

[tex](x-2)^2=4p(y-2)[/tex]

[tex](6-2)^2=4p(3-2)[/tex]

[tex](4)^2=4p(1)[/tex]

[tex]16=4p[/tex]

[tex]4=p[/tex]

Therefore:

Conclusion:

Review the graph for a visual

Answer:

(y/x)⁴

Step-by-step explanation:

14x^4y^6/7x^8y^2

= 2x^(-4)/2y^(-4)

= (y/x)⁴

Answer:

2y^4/x^2

Step-by-step explanation:

4x^4y^6 ÷ 7x^8y^2

you will find the GCF of the equation which is: 7x^4y^2 . Then, you will divide both of the equation by the GCF and it will become

14x^4y^6 ÷ 7x^4y^2 = 2y^4

7x^8y^2 ÷ 7x^4y^2 = x^2

then you'll get the answer 2y^4/x^2

Answer:

-1 1/3

Step-by-step explanation:

To find the mean, add up all the numbers

(-4+-3+-1+-1+0+1) =

-8

Then divide by the number of terms

-8/6

-4/3

-1  1/3

Answer A is your answer

Step-by-step explanation: