I REALLY NEED HELP PLEASE HELP ME :(

Answer:

(1) Variance = 4.5 and Standard deviation = 2.121.

(2) Variance = 4.5 and Standard deviation = 2.121.

(3) The effect on the measure of dispersion if each value is changed uniformly ​is that it remains unchanged.

Step-by-step explanation:

We are given with the following set of data below;

              X                     [tex]X-\bar X[/tex]                   [tex](X-\bar X)^{2}[/tex]

              5                   5 - 8 = -3                     9

              5                   5 - 8 = -3                     9

              8                   8 - 8 = 0                      0

             10                  10 - 8 = 2                     4

             10                  10 - 8 = 2                     4

             10                  10 - 8 = 2                     4

              9                   9 - 8 = 1                       1

              9                   9 - 8 = 1                       1

              6                  6 - 8 = -2                    4                

Total    72                                                   36      

Firstly, the mean of the above data is given by;

              Mean, [tex]\bar X[/tex]  =  [tex]\frac{\sum X}{n}[/tex]

                              =  [tex]\frac{72}{9}[/tex]  = 8

(1)Now, the variance of the given data is;

            Variance  =  [tex]\frac{\sum (X-\bar X)^{2} }{n-1}[/tex]

                                  =  [tex]\frac{36}{9-1}[/tex]  = 4.5

So, the standard deviation, (S.D.)  =  [tex]\sqrt{\text{Variance}}[/tex]

                                                        =  [tex]\sqrt{4.5}[/tex] = 2.12

(2) Now, each value is added by 2; so the new data set is given by;

              X                     [tex]X-\bar X[/tex]                   [tex](X-\bar X)^{2}[/tex]

              7                   7 - 10 = -3                     9

              7                   7 - 10 = -3                     9

             10                  10 - 10 = 0                     0

             12                  12 - 10 = 2                     4

             12                  12 - 10 = 2                     4

             12                  12 - 10 = 2                     4

              11                  11 - 10 = 1                       1

              11                  11 - 10 = 1                       1

              8                  8 - 10 = -2                    4                

Total    90                                                   36      

Firstly, the mean of the above data is given by;

              Mean, [tex]\bar X[/tex]  =  [tex]\frac{\sum X}{n}[/tex]

                              =  [tex]\frac{90}{9}[/tex]  = 10

(1)Now, the variance of the given data is;

            Variance  =  [tex]\frac{\sum (X-\bar X)^{2} }{n-1}[/tex]

                                  =  [tex]\frac{36}{9-1}[/tex]  = 4.5

So, the new standard deviation, (S.D.)  =  [tex]\sqrt{\text{Variance}}[/tex]

                                                                =  [tex]\sqrt{4.5}[/tex] = 2.12

(3) The effect on the measure of dispersion if each value is changed uniformly ​is that it remains unchanged as we see in the case of variance or standard deviation.

Answer:

5.7 meters

Step-by-step explanation:

Image a rectangle being cut diagonally in half, that would lead to two triangles. We can use the pythagorean theorem to find the missing side.

7 is the hypotenuse and 4 is the side length

4^2+x^2=7^2

16+x^2=49

sqrx=sqr(49-16)

x=sqr33

x=5.74

Rounded to the nearest tenth is 5.7

Answer:

12 pounds of Kenyan French Roast coffee

8 pounds of Sumatran coffee

Step-by-step explanation:

if you use x pounds of Kenyan French Roast coffee and y pounds of Sumatran coffee then you know that

11x + 10y = 10.6 * 20

x+y=20

10x+10y=200

11x+10y=212

x=12

y = 20-x = 20-12 = 8

so you want to use

12 pounds of Kenyan French Roast coffee

8 pounds of Sumatran coffee

Answer:

Step-by-step explanation:

2x ( -3y - 4) + 8 ( -3y - 4 )

= -6xy - 8x - 24y - 32

Hope this helps

plz mark as brainliest!!!

Answer:

Step-by-step explanation:

Use FOIL method

(2x + 8)(-3y -4) = 2x*(-3y) + 2x*(-4) + 8*(-3y) + 8*(-4)

                       = -6xy - 8x - 24y - 32

Step-by-step explanation:

If a line segment AB of length 6.6cm is drawn, bisecting it perpendicularly at N, we have two lines AN and NB of length 3.3cm each.

Because the line is bisected perpendicularly, the angles formed at the point of bisection are 90 degrees.

Answer:

Option D

Step-by-step explanation:

Given

[tex](5, 7), (7, 11). (9, 14). (11, 18)[/tex]

Required

Determine if the function is quadratic

[tex](5, 7), (7, 11). (9, 14). (11, 18)[/tex]

Start by representing the function as an x-y table

x:-  5 || 7 || 9 || 11

y:-  7 ||  11 || 14 || 18

Next; Calculate the difference between the values of y

[tex]Difference: 11 - 7 = 4[/tex]

[tex]Difference: 14 - 11 = 3[/tex]

[tex]Difference: 18 - 4 = 4[/tex]

The resulting difference are: 4 || 3 || 4

Next; Calculate the difference between the difference of values of y

[tex]Difference = 3 - 4 = -1[/tex]

[tex]Difference = 4 - 3 = 1[/tex]

The resulting difference are: -1 || 1

For the function to be quadratic, the above difference must be the same and since they are not, then the function does not represent a quadratic function.

Option D answers the question

Answer:

It's a (space) lot,... haha na I just kidding,... you're good,... I mean I'm not kidding cause it is correct,... but you are good,... like totally cool,... anyway,...

Step-by-step explanation:

By x the just mean what number,... so,...

what number + 6 = 7,

6 + what number = 7,

2 + what number + 5 = 7,

1 + what number = 7,

what number + 4 + what number = 7,

So that is what it mean,... hope it helps, alot LOL,... and,... Chow

Answer:

The present age of the woman is 37 years and her daughter is 7 years

Step-by-step explanation:

two years ago a woman was 7 times old as her daughter, but in 3 years time she would be 4 times old as the girl. how old are they now

Two years ago a woman wad 7 times as old as her daughter

Let her daughter=x-2

The woman=y-2

x-2

7(y-2)=7y-14

x-2=7y-14

x-7y=-14+2

x-7y= -12 (1)

but in 3 years time she would be 4 times as old as the girl.

x+3

y+3

x+3

4(y+3)=4y+12

x+3=4y+12

x-4y=12-3

x-4y=9. (2)

x-7y= -12 (1)

x-4y=9. (2)

Subtract (1) from (2)

4y-(-7y)=9-(-12)

-4y+7y=9+12

3y=21

y=21/3

y=7

Substitute

y=7 into (1)

x-7y= -12

x-7(7)=-12

x-49=-12

x= -12+49

=37

The present age of the woman is 37 years and her daughter is 7 years

Answer:

128

Step-by-step explanation:

3a² - 4b

plug in values

3(-6)² - 4(-5)

use PEMDAS and simplify (-6)² first

3(36) -4(-5)

multiply

108 + 20

add

128

hope this helps :)

Answer:

y = - 140

Step-by-step explanation:

The statement

y varies jointly as x & z is written as

to find y when x = 7 and z = -5 we must first find the relationship between the variables

when y = - 180

z = 15

x = - 3

- 180 = k(15)(-3)

-180 = - 45k

Divide both sides by - 45

k = 4

The formula for the variation is

when

x = 7

z = -5

y = 4(7)(-5)

y = 4(-35)

Hope this helps you

Answer:

Mary has 7 flowers

Peter has 1 flower

John has 2 flowers

Step-by-step explanation:

M + P + J = 10

J = 2P

M + P + 2P = 10

M + 3P = 10

P = 1

M + 3 = 10

M = 7

Answer:

see explanation (please confirm if I read you problem correctly)

Step-by-step explanation:

150 kilometers

60 kph

tank is 20 liters

6 km/l

150/6 = 25 liters needed

$60/l

you will need to get 5 more liters of fuel

total cost 25 x .60 =  $15

Answer:

AHHHHH I think its two hours

Step-by-step explanation:

she...? can drive 120 Kilometers before she runs out of fuel since the car's tank has 20 liters of fuel at the beginning of the drive, and its fuel efficiency is 6 kilometers per liter. and that means she can drive 2 hours

Answer:

0.4

Step-by-step explanation:

Given

[tex]\frac{0.2^3(8)}{0.4^2}[/tex]

= [tex]\frac{0.008(8)}{0.16}[/tex]

= [tex]\frac{0.064}{0.16}[/tex]

= 0.4

Answer:

-1

Step-by-step explanation:

Answer:

B

Step-by-step explanation:

Hypotenuse=sqrt(Side^2+side^2)=sqrt(14^2+14^2)=14*sqrt(2)

Answer:  

B  

Step-by-step explanation:  

Hypotenuse=sqrt(Side^2+side^2)=sqrt(14^2+14^2)=14*sqrt(2)

Answer:

b y=2.4x -1.8

Step-by-step explanation:

the equation y=2.4x -1.8 represents 2.4 from it

Answer:

=2x+3/4=5.50

x=19/8 or 2 3/8

hope this helps

Step-by-step explanation:

Answer:

D. 4(2x² + 4x - 6); 130.0 inches

Step-by-step explanation:

Margot is sewing a ribbon on a seam along the perimeter of a square pillow. The side length of the pillow is 2x²+1 inches. She plans to make a similar pillow, including the ribbon, whose side length is 4x−7 inches. What expression can be used for the length of ribbon that she needs for both pillows, and what is the length if x = 3.5?

2x2+4x−6; 22.0 inches

2x2+4x−6; 32.5 inches

4(2x2+4x−6;) 88.0 inches

4(2x2+4x−6;) 130.0 inches

Perimeter of a square = 4 * side length

1- First square pillow

length = 2x²+1 in

Perimeter of first pillow = 4 * (2x²+1) in

Second square pillow

length = 4x-7 in

Perimeter of second pillow = 4(4x-7) in

Total ribbon length required = perimeter of first square pillow + perimeter of second square pillow

Total ribbon length required = 4(2x²+1) + 4(4x-7)

Factorise

4 is the common factor

=4(2x²+1)+(4x-7)

=4(2x²+1+4x-7)

=4(2x²+4x-6)

Total ribbon length required=4(2x²+4x-6)

If x=3.5

Total ribbon length required=4(2x²+4x-6)

=4{2(3.5)²+4(3.5)-6}

=4{2(12.25)+14-6)

=4(24.5+14-6)

=4(32.5)

=130.0 inches

Answer:

Approximately [tex]58.28\; \rm m \cdot s^{-1}[/tex].

Step-by-step explanation:

The velocity of an object is the rate at which its position changes. In other words, the velocity of an object is equal to the first derivative of its position, with respect to time.

Note that the arrow here is launched upwards. (Assume that the effect of wind on Mars is negligible.) There would be motion in the horizontal direction. The horizontal position of this arrow will stays the same. On the other hand, the vertical position of this arrow is the same as its height: [tex]y = 62\, t - 1.86\, t^2[/tex].

Apply the power rule to find the first derivative of this [tex]y[/tex] with respect to time [tex]t[/tex].

By the power rule:

Therefore:

[tex]\begin{aligned}\frac{dy}{d t} &= \frac{d}{d t}\left[62 \, t - 1.86\, t^2\right] \\ &= 62\,\left(\frac{d}{d t}\left[t\right]\right) - 1.86\, \left(\frac{d}{d t}\left[t^2\right]\right) \\ &= 62 \times 1 - 1.86\times\left(2\, t) = 62 - 3.72\, t\end{aligned}[/tex].

In other words, the (vertical) velocity of this arrow at time [tex]t[/tex] would be [tex](62 - 3.72\, t)[/tex] meters per second.

Evaluate this expression for [tex]t = 1[/tex] to find the (vertical) velocity of this arrow at that moment: [tex]62 - 3.72 \times 1 =58.28[/tex].

Answer:

58.28 m/s

Step-by-step explanation:

y = 62t - 1.86t²

Speed, S = dy/dt = 62 - 2(1.86)t

S = 62 - 3.72t

When t = 1

S = 62 - 3.72 = 58.28 m/s

Answer:

Step-by-step explanation:

sorry it should be the second one for the interval notations

Answer:

6+4*(5-3)

Step-by-step explanation:

Because of PEMDAS l, we first solve in the parantheses. So 5-3 would be 2, then we multiply 2 by 4 which would be 8 obviously. Then we do the final step, add 6 and 8 which would be 14. Cheers!

Answer: 6 + 4 × (5-3)

Explanation:

6 + 4 × (5-3) = 14

6 + 4 × 2 = 14

6 + 8 = 14

14 = 14

Must click thanks and mark brainliest

Answer:

The last option

Step-by-step explanation:

When you have a fraction as a power, the denominator goes to the root, so in this case, it becomes root 4. The base, 5, goes to the outside, and the numerator 1, goes beside the x.

Hope this helps!

Answer:

[tex]n=10[/tex]

Step-by-step explanation:

[tex]\frac{4^8}{(4^2)^-^3}\ / 4^4=4^n[/tex]

Simplify, remember, an exponent raised to the power of another exponent is equal to the product of the two exponents,

[tex]\frac{4^8}{(4^2)^-^3}\ / 4^4=4^n[/tex]

[tex]\frac{4^8}{4^-^6}\ / 4^4=4^n[/tex]

Now bring the term in the denominator (number under the fraction bar) to the numerator (number over the fraction bar). This can be done by multiplying the exponent of the denominator by (-1).

[tex]\frac{4^8}{4^-^6}\ / 4^4=4^n[/tex]

[tex]4^8(4^(^-^1^)^(^-^6^))\ / 4^4=4^n[/tex]

Simplify,

[tex]4^8(4^6)\ / 4^4=4^n[/tex]

Remember, multiplying two numbers of the same base is the same as adding their exponents, apply this property here,

[tex]4^8(4^6)\ / 4^4=4^n[/tex]

[tex]4^1^4\ / 4^4=4^n[/tex]

Dividing two numbers of the same base is the same as subtraction their exponents,

[tex]4^1^4\ / 4^4=4^n[/tex]

[tex]4^1^0=4^n[/tex]

Thus, the following statement can be made,

[tex]4^1^0=4^n[/tex]

[tex]n=10[/tex]

Answer:

[tex]Average = 12\frac{4}{7}\ lb[/tex]

Step-by-step explanation:

Given

Number of jars = 14

Weights = 2, 2, 2, 1, 11, 12, 12, 2, 24, 22, 24, 3, 37, 22  in pounds

Required

What is the weight of each jar if the sea glass is evenly distributed

What this question implies is that, the average weight of the sea glass is calculated;

[tex]Average = \frac{Sum\ of\ weights}{Number\ of\ jars}[/tex]

[tex]Average = \frac{2+ 2+ 2+ 1+ 11+ 12+ 12+ 2+ 24+ 22+ 24+ 3+ 37+ 22}{14}[/tex]

[tex]Average = \frac{176}{14}[/tex]

[tex]Average = 12\frac{8}{14}[/tex]

Divide the numerator and denominator by 2

[tex]Average = 12\frac{4}{7}[/tex]

Hence, the weight of each jar would be [tex]12\frac{4}{7}\ lb[/tex]

Answer:

Well, we can write a really simple quadratic polynomial as:

P(x) = a*(x - c1)*(x - c2)

Where a is a constat, and c1 and c2 are the roots, here we have:

c1 = 5 and c2 = -3

P(x) = a*(x -5)(x + 3) = a*x^2 + a*x*3 - a*5*x - a*15

then the quadratic polynomial can be:

P(x) = a*x^2 + a*(3 - 5)*x - a*15

P(x) = a*x^2 - 2*a*x - a*15

Where a can be any real number.

Answer:

once upon a time a dude went to a store. there was a dude jacket for 20% off.

Step-by-step explanation:

Now do the opposite. for exapmle, the price increased by 20 %.

Answer:

$44.1

Step-by-step explanation:

March>>>>$40

for April: $40 × 5/100= $2 which is the 5% of $40.

Meaning for April Siti got $42

Then for May: $42 × 5 /100= $2.1 meaning she got $44.1 for May.

Answer:

2 3/8

Step-by-step explanation:

First get the LCM (Least Common Multiple) for the denominators so we can subtract them.  The denominators would both be 8 because it is the lowest number that they can have to be able to subtract.  (The LCM).  So is 4 3/4 has a denominator of 8 it'll become:

4 3/4= 4 6/8 because if 4 turned into 8, that means it multiplied by 2.  So, you need to multiply 3 by 2 as well which equals 6.  This is it as a ratio:

3:4 into x:8    

So 4 times 2, which means you need to do 3 times 2 as well.  It equals 6.

So now that we know 4 3/4 is 4 6/8, it is time to subtract.  2 3/8 already has a denominator of 8 so we don't need to do anything with that.  Subtract.

4 6/8-2 3/8= 2 3/8.  4-2=2, so the whole number is 2.  6-3= 3, so the numerator (the top number) is 3.  The denominator (the bottom number) always stays the same so it is the same, which is 8.

Step-by-step explanation:

w=3

4w^2-7w-8

4*3^2-7*3-8

4*9-21-8

4*9-29

36-29

7

hope this helps

Answer:

7

Step-by-step explanation: