Pls help I need help with 12

Answer:

Variance =10900.00

Standard deviation=104.50

Step by step Explanation:

Admissions Probability for 1100= 0.2

Admissions Probability for 1400=0.3

Admissions Probability for 1300 =0.5

To find the expected value, we will multiply each possibility by its probability and then add.

mean = 1100*0.2 + 1400*0.3 + 1300*0.5 = 1290

To find the variance, we will start by squaring each possibility and then multiplying it by its probability. We will then add these and subtract the mean squared.

E(X^2)=( 1100²*0.2)+ (1400²*0.3 )+ (1300²*0.5) = 1675000

Variance(X)=E(X²)- [E(X)]²

= 1675000 - (1290)²

=10900

Hence, the Variance(X)=10900

Then to calculate the standard variation , we will use the formular below,

standard variation (X)=√ var(X)= √10900

=104.5

Hence the standard variation=104.5

Answer:

y = 10

Step-by-step explanation:

y = 2x + 6

Let x  =2

y = 2*2 +6

y = 4+6

y = 10

Answer:

Step-by-step explanation:

[tex]y = 2x + 6 \\ x = 2 \\ y = 2(2) + 6 \\ y = 4 + 6[/tex]

[tex]y = 10[/tex]

A hexagon is composed of 6 congruent equilateral triangles. Each equilateral triangle has interior angle of 60 degrees. Adding 6 such angles together gets you to 360 degrees. So we've done one full rotation and covered every bit of the plane surrounding a given point. Extend this out and you'll be able to cover the plane. A similar situation happens with rectangles as well (think of a grid, or think of tiles on the wall or floor)

In contrast, a regular pentagon has interior angle 108 degrees. This is not a factor of 360, so there is no way to place regular pentagons to have them line up and not be a gap or overlap. This is why regular pentagons do not tessellate the plane. The same can be aside about decagons and octagons as well.

Answer:

i) x = 65°       ii)  x = 60°     iii)  x = 34°

  y = 50°           y = 80°           y = 124°

Step-by-step explanation:

i) x = 180-115= 65°

  y = 65+65= 130

     =  180-130= 50°  

ii) x = 90+30= 120

         180-120= 60°

   y = 60+20= 80

         180-80 = 100

         180-100= 80°

iii) y = 34+90= 124

    x = 180-124= 56

           56+90= 146

           180-146= 34°

I hope this helped, mark me brainliest please :)

Answer:

Quota Sampling

Step-by-step explanation:

Quota Sampling is a non-probability sampling method in research, where the researcher forms subgroups of individuals who are representative of the entire population through random selection. Quota sampling is often used by researchers who want to get an accurate representation of the entire population. It saves time and money especially if accurate samples are used.

In the example given above, where the research creates subgroups of 30 pre-school children by dividing them into 10 two-year-old children, 10 three-year-old, and 10 four-year-old children, he has applied the quota sampling.  These subgroups would give a proper representation of the preschool children in local daycare centers.

ok                                                         its 11 sqrt 6                                    

because if sqrt 6 is x, and 5x +6x=11x

so its 11 sqrt 6              

Answer:

2

Step-by-step explanation:

In order to make the equation undefined, you should make the denominator 0. Remember that dividing anything by 0 will become undefined.

[tex]2x-4=0\\\frac{2x=4}{2} \\x=2[/tex]

Answer:

[tex]\boxed{x = 2}[/tex]

Step-by-step explanation:

A rational expression is undefined when Denominator = 0

Here Denominator = 2x-4

So,

=> 2x - 4 = 0

Adding 4 to both sides

=> 2x = 4

Dividing both sides by 2

=> x = 2

Answer:

50

Step-by-step explanation:

Answer:

p(x) = (x + 1) (x - 3) (x + 2)

Step-by-step explanation:

x³ - 7x - 6

(x+1) (x² - x - 6) found by doing long division

(x+1) ( x - 3) (x + 2) are the factors

The polynomial p(x) as a product of linear factors is; p(x) = (x + 1) (x - 3) (x + 2)

They are mathematical expressions involving variables raised with non negative integers and coefficients(constants who are in multiplication with those variables) and constants with only operations of addition, subtraction, multiplication and non negative exponentiation of variables involved.

We are given the polynomial as;

x³ - 7x - 6

Then we found by doing long division;

(x+1) (x² - x - 6)

(x+1) ( x - 3) (x + 2)

These are the factors.

Hence, The polynomial p(x) as a product of linear factors is; p(x) = (x + 1) (x - 3) (x + 2)

Learn more about polynomials here:

https://brainly.com/question/27343162

#SPJ2

Answer:

k=5

a= -5

Step-by-step explanation:

if the polynomial x^4-6x^3+16x^2-25x+10 is divided by x^2-2x+k the remainder comes out to be x+a,find k and a

Solution

x^4-6x^3+16x^2-25x+10 / x^2-2x+k = x-a

We have,

(4k-25+16-2k)x+[10-k(8-k)] = x+a

(2k+9)x + (10-8k+k^2)=x+a

2k-9=1

2k=1+9

2k=10

Divide both sides by 2

2k/2=10/2

k=5

And

10-8k+k^2=a

10-8(5)+(5^2)=a

10-40+25=a

-5=a

Therefore, a=-5

x^4-6x^3+16x^2-25x+10 divided by x^2-2x+5 = x-5

Answer:

a proper fraction

Answer:

JK = 16√2

Step-by-step explanation:

This triangle is a special case right triangle, where you have 1 90-degree angle and 2 45-degree angles. The sides that correspond to the 45-degree angles are scalable by 1 and the hypotenuse is scalable by √2. Sometimes these are called 1-1-√2 triangles, describing the measurements of the sides.

Since this has a side of 16, the hypotenuse will be 16√2.

Cheers.

Answer:

Option B

Step-by-step explanation:

When we compare the number of shirt with it's cost, we find out that 8 shirts cost $120.

For more understanding, see the attached file.

Answer:

17 cans

Step-by-step explanation:

18 cans

7 are taken away

18-7 =11

Then we put 6 back on

11+6 = 17

There are now 17 cans

Answer: The fifth piece of paper could have any number 9 and less or 14 and greater.

Step-by-step explanation:  The list of choices is not given in the question, but it makes sense that the new number would not be a duplicate of any of the numbers 10, 11, 12, 13. Otherwise that would change the probability to 5/5.

So any other number could be a possibility.

31

because 15 +16 :31

[tex]. = y1 = \times [/tex]

Answer:

5[tex]\sqrt{2}[/tex]

Step-by-step explanation:

The diagonal divides the square into 2 right triangles.

let s be the side of the square with the diagonal being the hypotenuse.

Applying Pythagoras' identity to one right triangle, gives

s² + s² = 10² , that is

2s² = 100 ( divide both sides by 2 )

s² = 50 ( take the square root of both sides )

s = [tex]\sqrt{50}[/tex] = [tex]\sqrt{25(2)}[/tex] = [tex]\sqrt{25}[/tex] × [tex]\sqrt{2}[/tex] = 5[tex]\sqrt{2}[/tex]

Answer:

length=25m

breadth=10m

Step-by-step explanation:

2.5units+2.5units+1unit+1unit=7units

70/7=10

length=10x2.5=25

breadth=10

(sorryy im not really sure but i hope it helps :D)

Answer:

Length = 25 cm

Breadth = 10 cm

Step-by-step explanation:

Let breadth of the room be 'x'

Let length of the room be ''

Perimeter ( P ) = 70 cm

Now, let's find the breadth of the room 'x '

Perimeter of rectangle =  2(l+b)

plug the values

70=2(2.5x+x)

Collect the like terms

70=2x3.5x

Calculate the product

70=7x

Swap the sides of the equation

7x=70

Divide both sides of the equation by 7

7x / 7= 70/7

Calculate

x=10cm

Breadth = 10 cm

Now, Let's find the length of the room ' 2.5x '

Length of the room =  2.5x

Plug the value of X

2.5x10

Calculate the product

25cm

Thus , The length and breadth of the room is 25 cm and 10 cm respectively.

Hope this helps..

Best regards!!

Answer:

80 in²

Step-by-step explanation:

8/10 = x/100

x = 80

Answer:

No there is not  enough evidence to support the claim that the mean expenditure for auto insurance is less than the 2002 amount at the α = 0.05 level of significance

Step-by-step explanation:

Sample Mean = μ1 = $806

Sample Mean = μ2 = $ 781

Standard Deviation= S= σ =39.13

n= 32

Confidence Interval = 95 %

α= 0.05

z∝=± 1.96

We state the null and alternative hypotheses as

H0: μ1 = $806  and Ha: μ1 ≠ $806  two sided tail test

z= μ1 -μ2/σ/√n

z= 806-781/ 39.13/√32

z= 806-781/ 39.13/5.6568

z=806-781/ 6.92

z= 25/6.92

z= 3.613

Z> z∝

3.613 > ± 1.96

No there is not  enough evidence to support the claim that the mean expenditure for auto insurance is less than the 2002 amount at the α = 0.05 level of significance

Answer: Jennifer didn't randomly assign participants to the control and experimental group.

Step-by-step explanation: In the scenario discussed above, Jennifer failed to perform a random assignment of the participants who took part in the survey, that is the experimental group, those who receive the treatment and the control group, those who don't. Random assignment is required in other to address the issue of bias in our experiment. She was supposed to perform a random assignment of the participants to the two groups instead of asking them to make a choice.

Answer:

Step-by-step explanation:

First, we can find the measures of center for each group.

Group A

Mode: 1

Median: (1 + 2) / 2 = 3 / 2 = 1.5

Mean: (1 * 5 + 2 * 4 + 3) / 10 = (5 + 8 + 3) / 10 = 16 / 10 = 1.6

Group B

Mode: 3

Median: 92 + 3) / 2 = 5 / 2 = 2.5

Mean: (1 * 3 + 2 * 2 + 3 * 4 + 5) / 10 = (3 + 4 + 12 + 5) / 10 = 24 / 10 = 2.4

From here, we can see that...

Hope this helps!

Answer:

ABC

Step-by-step explanation:

Answer:

x=4

Step-by-step explanation:

First you need to factor the equation. You can do this by multiplying the numbers by eachother so they have a denominatior of 12.

You would come out to have this...

((x+2)*4)/12 + ((2x-4)*3)/4=3

At this point you can combine the numerators over the common denominator.

((x+2)*4+(2x-4)*3)/12=3

You can now rewrite the equation into factored form.

5x-2/6=3

Multiply both sides of the equation by 6.

5x-2=18

move the terms not containing x to the right

5x=20

and divide by 5

x=4

There's a bit of ambiguity in your question...

We know that [tex]f^{-1}(-15)=7[/tex], which means [tex]f(7)=-15[/tex].

I see three possible interpretations:

• If [tex]f(x)=k\sqrt2+x[/tex], then

[tex]f(7)=-15=k\sqrt2+7\implies k\sqrt2=-22\implies k=-\dfrac{22}{\sqrt2}=11\sqrt2[/tex]

• If [tex]f(x)=k\sqrt{2+x}[/tex], then

[tex]f(7)=-15=k\sqrt{2+7}\implies -15=3k\implies k=-5[/tex]

• If [tex]f(x)=\sqrt[k]{2+x}[/tex], then

[tex]f(7)=-15=\sqrt[k]{2+7}\implies-15=9^{1/k}\implies\dfrac1k=\log_9(-15)[/tex]

which has no real-valued solution.

I suspect the second interpretation is what you meant to write.

Answer:

a) $26.4

b) $324

Step-by-step explanation:

Hire purchase is the purchase of an item which can be paid instalmentally.

The bicycle costs $300 for an instant purchase.

For a hire purchase, a $60 deposit must be made and the rest paid instalmentally over 10 months. An interest of 10% is included in the outstanding balance

The outstanding balance after paying deposit= $300 - $60 = $240

Hence, 10% of 240 = 10/100 × 240 = 24

An interest of $24 is added.

Therefore, a total of $240 + $24 = $264 will be paid for the next 10 months.

a) Hence, the amount to be paid in instalment each month is $264/10 = $26.4

b) the total cost of buying the bicycle by hire purchase= deposit amount + instalment price

= $60 + $264

= $324

Hence, a total of $324 will be paid for the bicycle by hire purchase.

N.B: $300 is the sale price + $24 interest

Answer: 270 chocolates

Step-by-step explanation:

Given the following :

Number of 5-year Olds = 5

Number of 6-year Olds = 5

Number of 7-year Olds = 5

Number of chocolates received by each child = 3 times as many chocolate as their age.

Number of chocolates received by 5-year Olds = 3 × 5 = 15 chocolates

Number of chocolates received by 6-year Olds = 3 × 6 = 18 chocolates

Number of chocolates received by 7-year Olds = 3 × 7 = 21 chocolates

Total Number of chocolates received by 5-year Olds = 5 * 15 = 75 chocolates

Total Number of chocolates received by 6-year Olds = 5 * 18 = 90 chocolates

Total Number of chocolates received by 7-year Olds = 5 * 21 = 105 chocolates

Totak number of chocolates altogether :

(75 + 90 + 105) = 270 chocolates

Answer:

The board game store

Step-by-step explanation:

Just divide the store price by 4 and online by 5

Answer:

Toy store

Step-by-step explanation:

Let's find the unit rates for the toy store and the online store. To find the unit rate, divide the price by the number of board games.

price/board games

Toy Store

price/board games

The toy store sells 4 board games for $25.84

$25.84 / 4 board games

25.84/5

6.46

Online Store

price/ board games

The online store sells 5 board games for $32.15

$32.15 / 5 board games

32.15/5

6.43

At the toy store, a board game costs $6.46. Online, it costs $6.43.

6.46 is greater than 5.43, therefore, the toy store has the higher price for a board game.

Answer: It is option 2 or B

Step-by-step explanation: Simple and easy, the test said it was right too.