I need answer asap plz

Question a) Compare the Variability of Expenditure of Families in Two Towns given as follows: Number of families Expenditure (Ru

Karolina [17]

Answer:

Kindly check explanation

Step-by-step explanation:

Given the data:

Number of families __________Expenditure

______midpoint (x) ____Town A __Town B

21-30 __25.5____________3 _______2

31-40 __35.5____________61 ______14

41-50 __45.5___________132 _____ 20

51-60 __55.5__________ 153 ______27

61-70 __65.5__________ 140 ______ 28

71-80 __75.5___________ 51 _______ 7

81-90 __85.5___________ 2 _______ 2

The variability is the variance and standard deviation :

The variance (s):

√Σ(x - m)²/Σf(x)

Town A:

m = Σ(X * f(x)) / Σf ; Σf = 542

Σ x * f(x) = (25.5*3) + (35.5*61) + (45.5*132) + (55.5*153) + (65.5*140) + (75.5*51) + (85.5*2)

= 29931 / 542

= 55. 22

Σf(x - m)² / Σf - 1 = [3(25.5-55.22)^2 + 61(35.5-55.22)^2 + 132(45.5-55.22)^2 + 153(55.5-55.22)^2 + 140(65.5-55.22)^2 + 51(75.5-55.22)^2 + 2(85.5-55.22)^2] / 541

= 76458. 4928 / 541

Variance = 141.32808

Standard deviation = √variance

Standard deviation = √141.32808

Standard deviation = 11.89

TOWN B:

m = Σ(X * f(x)) / Σf ; Σf = 100

Σ x * f(x) = (25.5*2) + (35.5*14) + (45.5*20) + (55.5*27) + (65.5*28) + (75.5*7) + (85.5*2)

= 5490 / 100

= 54.90

Variance :

Σf(x - m)² / Σf - 1 = [2(25.5-54.90)^2 + 14(35.5-54.90)^2 + 20(45.5-54.90)^2 + 27(55.5-54.90)^2 + 28(65.5-54.90)^2 + 7(75.5-54.90)^2 + 2(85.5-54.90)^2] / 99

= 16764 / 99

= 169.33

Standard deviation = √variance

Standard deviation = √169.3333

Standard deviation = 13.013

From the result above, Town A has lesser variability than Town B due to the slightly lower variance and standard deviation values.

8 0

3 years ago

WILL MARK BRAINLIEST!!! A contractor has 34 meters of fencing that he is going to use as the perimeter of a rectangular garden.

snow_tiger [21]

Given

Shape of garden: Rectangle

Perimeter: 34 meters

Area: 72 square meters

Length of one side = x

Required

Find the dimension of the rectangle

Let the length of the other side of the rectangle be represented with y.

We start by writing out the perimeter of a rectangle

Perimeter, P = 2(L + B)

Where P is the perimeter; L and B are the length and width of the sides of the rectangle.

In this case L and B are represented by x and y

So,

P = 2(x + y)

By substituting 34 for P

34 = 2(x + y)

Multiply both sides by ½

½ * 34 = ½ * 2(x + y)

17 = x + y

Make y the subject of formula

y = 17 - x

Recall that the sides of the rectangle are represented by x and y.

Hence, the area of the rectangle is as follows.

Area = x * y

Substitute 72 for Area and 17 - x for y

72 = x(17 - x) --- Open bracket

72 = 17x - x² ---- Reorder

x² - 17x + 72 = 0

Now, we have a quadratic equation

Solving by factorisation

x² - 8x - 9x + 72 = 0

x(x - 8) - 9(x - 8) = 0

(x - 8)(x - 9) = 0

x - 8 = 0 or x - 9 = 0

x = 8 or x = 9

Recall that

y = 17 - x.

When x = 8

y = 17 - 8

y = 9

When x = 9

y = 17 - 9

y = 8

Writing out the result, we have

x = 8 , y = 9

Or

x = 9, y = 8

Hence, the dimension of the rectangle is 8 metres by 9 metres

7 0

3 years ago

A balloon rises at the rate of 10 ft/sec from a point on the ground 100 feet from an observer. Find the rate of change of the an

lubasha [3.4K]

The rate of change of the angle of elevation of the balloon from the observer when the balloon is 100 feet above the ground is 1/20 degree/sec.

<h3>What is angle of elevation?</h3>

It is described as a relationship between an oblique line from the observer's eye to an item above his eye and the horizontal plane. This angle eventually develops above the surface. The angle of elevation is made in such a way that it is above the observer's eye, as the name suggests.

Calculation for the rate of change of angle of elevation-

According to the question,

A balloon rises at the rate of 10 ft/sec from a point on the ground 100 feet from an observer.

The balloon is 100 feet above the ground.

Let the height of the balloon be 'h' ft.

Then tanØ = h/100

h = 100tanØ

Differentiate the above equation with respect to time.

dh/dt = 100 sec² Ø (dØ/dt)

We know dh/dt = 10 ft/sec.

when h = 100

tanØ = 100/100 = 1/1

tanØ = Perpendicular/Base

On comparing above two equations,

Perpendicular = 1; Base = 1.

By Pythagoras the hypotenuse is,

H² = P² + B²

= 1² + 1²

= 2

H = √2

Now, calculate the value of cosØ.

cosØ = B/H = 1/√2

Squaring both side

cos² Ø = 1/2

sec² Ø = 1/cos² Ø

sec² Ø = 2

The main equation was,

dh/dt = 100 sec² Ø (dØ/dt)

Substitute the values,

dØ/dt = (dh/dt )/100 sec² Ø

= (10)/(100×2)

dØ/dt = 1/20 degree/sec.

Therefore, the rate of change of the angle of elevation of the balloon from the observer is 1/20 degree/sec.

To know more about the angle of elevation, here

brainly.com/question/9817377

#SPJ4

8 0

1 year ago

Determine whether ∆DEF=∆JKL, given that D(2,0), E(5,0), F(5,5), J(3,-7), K(6,-7), and L(6,-2)

raketka [301]

Answer:

Yes , triangle DEF is congruent to JKL

Step-by-step explanation:

Given:

The coordinates of triangle DEF are;

D (2, 0)

E(5. 0)

F(5, 5)

and

the coordinates of triangle JKL are:

J(3, -7)

K(6, -7)

L (6, -2)

The rule of translation is used on triangle DEF to get triangle JKL:

$(x , y) \rightarrow (x+1 , y-7)$

i.e

$D (2, 0) \rightarrow (2+1 , 0-7) = (3, -7)$ = J

$E (5, 0) \rightarrow (5+1 , 0-7) = (6, -7)$ = K

$F (5, 5) \rightarrow (5+1 , 5-7) = (6, -2)$ = L

As, we know that two triangles are known as congruent if there is an isometry mapping one of the triangles to the other.

therefore, triangle DEF congruent to triangle JKL

8 0

3 years ago

Please help stattttttttttttttttttt

Ivahew [28]

Fish tank A
V = Ah = 25 ft^2 * 8 ft = 200 ft^3

Fish tank B
V = Ah = 40 ft^2 * 4 ft = 160 ft^3

The volume of fish tank A is 200 ft^3, and the volume of fish tank B is 160 ft^3, so fish tank A has a greater volume. Its volume is greater by 40 ft^3.

4 0

3 years ago