The table shows the probability distribution of siblings of students in a high
school with 1500 students. What is the expected value for the number of
siblings of a randomly chosen student?
Number of siblings
0
1
2
3
4
5
Probability
0.18
0.65
0.09
0.05
0.02
0.01
A. 1.08
B. 2.5
C. 1.11
D. 1.29

Answer:

Step-by-step explanation:

36 - 4

Step-by-step explanation:

(6x - 2)(6x + 2)

= (6x)(6x) + (6x)(-2) + (2)(6x) + (-2)(2)

= 36 - 12x + 12x - 4

= 36 - 4

Answer:

Part A:

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

x is a binomial Random Variable.

Part B:

Value of p=0.8

Value of n=20

Part C:

P(X=15)=0.17456

Part D:

P(X≥15)=0.80417

Part E:

E(x)=16

E(x) tells us that out of 20 tracks the SBIRS will detect from 16 tracks.

Step-by-step explanation:

Part A:

Binomial Distribution is used because the number of tracks and the probability to find the intruding object is constant for all tracks

It means:

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

x is a binomial Random Variable.

Part B:

Value of p=0.8

Value of n=20

Part C:

x=15

[tex]P(X=15)=20_{C_{15}}*0.8^{15}*(1-0.8)^{20-15}\\[/tex]

By solving above Expression:

P(X=15)=0.17456

Part D:

P(X≥15)=P(X=15)+P(X=17)+P(X=16)+P(X=18)+P(X=19)+P(X=20)

[tex]P(X=15)=20_{C_{15}}*0.8^{15}*(1-0.8)^{20-15}\\[/tex]

P(X=15)=0.17456

[tex]P(X=16)=20_{C_{16}}*0.8^{16}*(1-0.8)^{20-16}\\P(X=16)=0.21819[/tex]

[tex]P(X=17)=20_{C_{17}}*0.8^{17}*(1-0.8)^{20-17}\\P(X=17)=0.20536[/tex]

[tex]P(X=18)=20_{C_{18}}*0.8^{18}*(1-0.8)^{20-18}\\P(X=18)=0.13691\\\\P(X=19)=20_{C_{19}}*0.8^{19}*(1-0.8)^{20-19}\\P(X=19)=0.05765\\\\P(X=20)=20_{C_{20}}*0.8^{20}*(1-0.8)^{20-20}\\P(X=20)=0.01153[/tex]

Now, Adding Probabilities:

[tex]P(X=15)+P(X=17)+P(X=16)+P(X=18)+P(X=19)+P(X=20)\\=0.17456+0.21819+0.20536+0.13691+0.05765+0.01153\\[/tex]

P(X≥15)=0.80417

Part E:

Mean Distribution:

E(x)=n*p

E(x)=20*0.8

E(x)=16

E(x) tells us that out of 20 tracks the SBIRS will detect from 16 tracks.

Answer:

A = 35.42 yd²

Step-by-step explanation:

We need to find the area if the dimensions are given as 4.6 yd  and 7.7 yd.

The area of a rectangle shaped figure is given by :

A = lb

Where

l is length and b is the breadth

So, put all the values,

A = (4.6)(7.7)

= 35.42 yd²

So, the area of the figure is equal to 35.42 yd².

Answer:

The 90% confidence interval for the mean amount spent on the children's birthday gift is between $45.77 and $48.23.

Step-by-step explanation:

We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 18 - 1 = 17

90% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 17 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.9}{2} = 0.95[/tex]. So we have T = 1.7396

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 1.7396\frac{3}{\sqrt{18}} = 1.23[/tex]

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 47 - 1.23 = $45.77

The upper end of the interval is the sample mean added to M. So it is 47 + 1.23 = $48.23

The 90% confidence interval for the mean amount spent on the children's birthday gift is between $45.77 and $48.23.

Answer:

58°

Step-by-step explanation:

A flat angle equals 180°, so we can simply subtract the given angle from the total, 180.

180 - 122 = 58

So, ∠CDE = 58°.

Good luck n.n

Answer:

58°

Step-by-step explanation:

∠AEC =∠AED+∠CED

So,

∠AEC=180°

∠AED=122°

∠CED=?

∠AEC =∠AED+∠CED

180°=122°+∠CED

∠CED=180°-122°

∠CED=58°

Answer:

64 and 65536

Step-by-step explanation:

you just multiply everything

6.55 months? i dont know for sure but i tried

Answer:

9

Step-by-step explanation:

10 subtract 1 is 9.

Given:

10 people ate pie

1 person ate cake

No of people who ate the pie than the cake

10-1 =9

Answer:

I got 3 hours and 10 minutes

Step-by-step explanation:

If you continuously add numbers in decimal form you will find the answer also.

But also another way in order to find a time answer you could also subtract

7.50-4.40= 3.10

or just 3.1 in this case.

But in a time frame always add the 0 to it.

So 3 hours and 10 minutes!

I think so indeed.

Answer:

x = 9

y = 8

Step-by-step explanation:

We can find the value of x and y using similarity ratio because the triangles are similar

6/4 = x/6 cross multiply expressions

4x = 36 divide both sides by 4

x = 9

same goes with y

6/4 = 12/y cross multiply expressions

6y = 48 divide both sides by 6

y = 8

Answer:

12°

Step-by-step explanation:

Let's start with the easy first.

We know that m∠C is 39° because together ∠C and the exterior angle equal 180°. And 180 - 141 = 39.

Now, we can use this to find the remaining two angles.

180° - 39° = 141°

So, this means that we can set up m∠A + m∠B = 141°.

6x + 9 + x - 8 = 141

7x + 1 = 141

7x = 140

x = 20

Finally, we can plug in for our x value and find m∠B.

m∠B = x - 8

m∠B = 20 - 8

m∠B = 12°

Answer:

12

Step-by-step explanation:

[tex]\huge{\textbf{\textsf{{\color{navy}{An}}{\purple{sw}}{\pink{er}} {\color{pink}{:}}}}}[/tex]

C. 4.

Answer:

34.4 yds3

Step-by-step explanation:

tuve la misma pregunta hoy

Answer:

je -parle

tu - parles

il/elle/on - parle

nous - parlons

vous - parlez

ils/elles - parlent

Answer:

Verbs with infinitives ending in -er form a second group of regular verbs in Spanish, often called second conjugation verbs.

Step-by-step explanation:

To conjugate these verbs in the present tense, drop the -er from the infinitive and add the second conjugation present tense endings: -o, -es, -e, -emos, -en.

Answer:

5x^2 + 2

Step-by-step explanation:

pretty sure

Answer:

6.25

Step-by-step explanation:

x+2=5x

2= -x+5x

2=4x

2/4=4x/4

1/2=x

Plug into formla of rectangel: L*W

L= 5(0.5)= 2.5

W= 0.5+2 = 2.5

L*W= 2.5*2.5 = 6.25

Answer:

16 3/4=[16×4+3]/4=67/4 is your answer

Answer:

The area of the shaded region of the figure in the exercise is:

Step-by-step explanation:

To obtain the area of irregular shapes, you can divide that shape in figure you know and you can obtain the area, first, we're gonna calculate the area of the right side and the left side with the formula below:

How the left rectangle and the right rectangle have the same measurements, we can say:

You can see in the center there is a rectangle too, but you need just a half formed by a triangle, you can use two form for this: calculating the area of the triangle or calculating the area of the whole rectangle and next to divide in 2, we're gonna use the first:

In the exercise, the base of the shaded triangle is 2.7 inches, and the height you must add the measurements in the right side:

Now we replace in the formula:

By last, you must add all the calculated areas from the shaded regions:

Answer:

d radias

Step-by-step explanation:

The another way to look at the circumference of a circle is the perimeter of the circle. Option A is correct.

The circumference of the circle is the length of its boundary. It can found out using the following formula,

[tex]P=2\pi r[/tex]

Here, (r) is the radius of the circle.

Thus, the another way to look at the circumference of a circle is the perimeter of the circle. Option A is correct.

Learn more about the circumference of the circle here;

https://brainly.com/question/402655

Answer: C. 5x+6(-x+4)=13

Step-by-step explanation: When you substitute you just put the equation in not the variables.

Options A and D don't give a solution and B includes the variable y.

Answer:

1

Step-by-step explanation:

Answer:

Step-by-step explanation:

The mode is the number which occurs most frequently in the data set.

In this question, 1 appears the most frequently meaning that the correct mode is is 1.

Answer:

75

120

Step-by-step explanation:

Let the first mechanic's hourly rate = x

Let the second mechanic's hourly rate = y

x + y = 195

15x + 5y = 1725        Divide this equation by 5

3x + y = 345             Write the first equation below this one. Subtract

x   + y = 195

2x = 150                    Divide by 2

x = 150/2

x = 75

====================

x + y = 195

75 + y = 195

y = 195 - 75

y = 120

Basically, you have to understand the logic of a function.

If I plug in a value into V that represents the value of a milling machine, if I simplify the equation, I will be able to find x, the corresponding time to the value of the milling machine.

Knowing this logic, we can plug in $450,000 and $480,000, and then we will have two x-values. Then we can just find the range of the x-values to find our answer! :)

Let's go.

V = 750,000 - 120x

Plugged in 450,000 for V so now we can simplify the equation and find out what is the corresponding x-value for this value at this certain time.

450,000 = 750,000 - 120x

-450,000  -450,000

0 = 750,000 - 120x

+120x on both sides to isolate x

120x = 300,000

x = 2500

So, our first x-value in the range is 6250 hours. Now, let's plug in the larger value to find out the other x-value in the range.

V = 750,000 - 120x

480,000 = 750,000 - 120x

-480,000  -480,000

0 =  270,000 - 120x

Add 120x on both sides to isolate x

120x = 270,000

x = 2250

So, we found 2250 and 2500. So, the range of hours it corresponds to is 2250-2500.

Answer:

attached below

Step-by-step explanation:

a) Diagram of state transition representing failure and repair process of component

attached below

b) expression for the system to be completely available

attached below

c) Expression for system to be operating in a degraded mode

attached below

Answer:

after 35 hours she makes 11.75 an hour

Step-by-step explanation:

Answer:

Your source water comes from the Detroit River, situated within the Lake St. Clair, Clinton River, Detroit River, Rouge River and Ecorse River watersheds in the U.S., and parts of the Thames River, Little River, Turkey Creek and Sydenham watersheds in Canada.

Step-by-step explanation:

please mark this answer as brainliest

Answer:

$17.50

Step-by-step explanation:

multiply 25 and 30, the divide the answer by 100, the deduct that result from the original price

Answer:

20 adults

100 Children

Step-by-step explanation:

Answer: 20 adults and 100 children

Step-by-step explanation:

a = adults, c = children

120 = a + c

c = 5a

120 = a + 5a

120 = 6a

20 = a

20 times 5 is 100 so 100 children