A shirt is on sale for 20% off its original price. If the shirt cost $40, how much will the shirt cost after the discount?
$8
$20

Answer:

CI 99% = (  0,022  ;  0,126 )

Step-by-step explanation:

First sample  

n₁  = 500

x₁  = 48

p₁ = x₁ / n₁   =  48 / 500      p₁  =  0,096      p₁  = 9,6 %

Second sample

n₂  = 400

x₂  = 68

p₂ = x₂ / n₂   =  68 / 400      p₂  =  0,17       p₂  = 17 %

CI = 99 %    significance level α = 1 %     α  = 0,01

z(c)  for α = 0,01  is from z- table    z(c) = 2,325

CI  =  ( p₂ - p₁ ) ±  z(c) *√ p*q* ( 1/n₁  +  1 / n₂ )

Where

p₂  -  p₁  =  0,17 - 0,096 = 0,074

p = ( x₁ + x₂ )  / n₁ + n₂

p =  ( 48  +  68  ) /( 500 + 400)

p = 116/ 900     p = 0,1288     and   q = 1 - p     q  = 0,8712

z(c) *√ p*q* ( 1/n₁  +  1 / n₂ ) = 2,325 * √ 0,1288*0,8712 ( 1 / 500 + 1/ 400)

2,235 * 0,02247

z(c) *√ p*q* ( 1/n₁  +  1 / n₂ ) = 0,052

Then

CI 99 %  =  0,074  ±  0,052

CI 99% = (  0,022  ;  0,126 )

The difference between the groups shows that the proportion in the second group was bigger than in the first group.

The CI in the context of the problem is  CI 99% = (  0,022  ;  0,126 )

Given first sample is  

n₁  = 500

x₁  = 48

  [tex]P_{1} =\dfrac{X_{1} }{n_{1} }[/tex]      [tex]P_{1} =\dfrac{48}{500}[/tex]      

p₁  =  0,096      p₁  = 9,6 %

Given second sample

n₂  = 400

x₂  = 68

[tex]P_{2} =\dfrac{X_{2} }{n_{2} }[/tex]      [tex]P_{2} =\dfrac{68}{400}[/tex]        

p₂  =  0,17       p₂  = 17 %

Since given CI = 99 %    so significance level  α = 1 %     α  = 0,01

From Z-Table  z(c)  for α= 0,01  is = 2,325

CI  =   [tex](P_{2} -P_{1}[/tex]   ±    [tex]Z(c)\sqrt[2]{p\times q} (\dfrac{1}{n_{1} } +\dfrac{1}{n_{2} } )[/tex]  

Where

p₂  -  p₁  =  0,17 - 0,096 = 0,074

[tex]P= \dfrac{X_{1} +X_{2} }{n_{1}+n_{2} }[/tex]

[tex]P=\dfrac{48+68}{500+400}[/tex]

[tex]P=\dfrac{116}{900}[/tex]

p = 0,1288     and   q = 1 - p     q  = 0,8712

[tex]Z(c)\sqrt[2]{p\times q} (\dfrac{1}{n_{1} } +\dfrac{1}{n_{2} } )[/tex]  [tex]2325\times\sqrt[2]{0.1288\times 0.8712} (\dfrac{1}{500_{} } +\dfrac{1}{400_{} } )[/tex]

  [tex]Z(c)\sqrt[2]{p\times q} (\dfrac{1}{n_{1} } +\dfrac{1}{n_{2} } )=0.052[/tex]

Then

CI 99 %  =  0,074  ±  0,052

CI 99% = (  0,022  ;  0,126 )

Hence the difference between the groups shows that the proportion in the second group was bigger than in the first group.

To know more about Chi square follow

https://brainly.com/question/4543358

Answer:

x = 6.5

Step-by-step explanation:

Reference angle = 54°

Length of Side opposite to 54° = x

Hypotenuse = 8 cm

Recall: SOHCAHTOA.

Apply SOH:

Sin 54 = Opp/Hyp

Sin 54 = x/8

x = 8*sin 54

x = 6.47213595 ≈ 6.5 cm (nearest tenth)

Answer:

The pvalue of the test is 0.03 > 0.01, which means that we fail to reject the null hypothesis at the 0.01 level.

Step-by-step explanation:

The company's promotional literature states that 47% of the chips do not fail in the first 1000 hours of their use. The quality control manager wants to test the claim that the actual percentage that do not fail is different from the stated percentage.

This means that at the null hypothesis we test that the proportion is 47% = 0.47, that is:

[tex]H_0: p = 0.47[/tex]

And at the alternate hypothesis, we test that the proportion is different from 47%, that is:

[tex]H_a: p \neq 0.47[/tex]

The test statistic is:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.

47% is tested at the null hypothesis:

This means that [tex]\mu = 0.47, \sigma = \sqrt{0.47*0.53}[/tex]

A sample of 1300 computer chips revealed that 50% of the chips do not fail in the first 1000 hours of their use.

This means that [tex]n = 1300, X = 0.5[/tex]

Value of the test statistic:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

[tex]z = \frac{0.5 - 0.47}{\frac{\sqrt{0.47*0.53}}{\sqrt{1300}}}[/tex]

[tex]z = 2.17[/tex]

Pvalue of the test and decision:

The pvalue of the test is the probability that the proportion differs from 0.47 by at least 0.5 - 0.47 = 0.03, which is P(|Z| > 2.17), which is 2 multiplied by the pvalue of Z = -2.17

Z = -2.17 has a pvalue of 0.015

2*0.015 = 0.03

The pvalue of the test is 0.03 > 0.01, which means that we fail to reject the null hypothesis at the 0.01 level.

Answer: hey bro i can solve this for you but you need to show the quadrilateral. without it i can't solve it.

Step-by-step explanation:

Answer:

392 ft²

Step-by-step explanation:

The composite figure can be divided into a rectangle, 2 triangles and a square

Area of rectangle = Length * width

Area of rectangle = 21 feets * 14 feets = 294 feet²

Area of triangle = 0.5 * base * height

Area of triangle = 0.5 * 7 * 7 = 24.5

AREA of square = a² = 7² = 49 feets²

Total area :

294 feets + (2 * 24.5) feets² + 49 feets²

294 + 49 + 49 = 392 ft²

Answer:

c Melindas account will have about 5.40 more than olivia's account

Step-by-step explanation:

Answer:

Step-by-step explanation:

Answer:

Step-by-step explanation:

Part A

we have to solve the associated equation

4a^2 - 20a + 25 = 0

first of all we have to find the delta/4

Δ/4 = (b/2)^2 - ac  where a is the term that multiply a^2, b is the term that multiply a and c is the therm without the variable

Δ/4 = (-10)^2 -100 = 100-100 = 0

the delta is equal to 0 that is mean that the equation has two coincident solutions, that can be find thanks to this formula

a1,a2 = -b/2/a = 10/4 = 5/2

now we can factorize the trinomial in this way:

4(a-5/2)(a-5/2)

4[(2a-5)/2][(2a-5)/2]

(2a-5)(2a-5)

the side of the square is 2a-5

Part B

the area of the rectangle is expressed as difference by two squares, so it can be rewritten as

(3a+4b)(3a-4b)

so the dimension of the rectangle are

3a+4b and 3a-4b

Answer:

The critical value that should be used is T = 2.0796.

The 95% confidence interval for the mean repair cost for the dryers is between $91.912 and $105.648.

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 = 22 - 1 = 21

95% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 21 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.95}{2} = 0.975[/tex]. So we have T = 2.0796, which is the critical value that should be used.

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 2.0796\frac{15.49}{\sqrt{22}} = 6.868[/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 98.78 - 6.868 = $91.912

The upper end of the interval is the sample mean added to M. So it is 98.78 + 6.868 = $105.648

The 95% confidence interval for the mean repair cost for the dryers is between $91.912 and $105.648.

Answer:

√11 = 3.31....

option 1. Irrational: √11 = 3.3

Answer:

Irrational [tex]\sqrt{11}[/tex] = 3.3

Step-by-step explanation:

Have a nice day!! :)

Answer:

A qualitative variable, also called a categorical variable, is a variable that isn't numerical.

Answer:

434 [tex]cm^3[/tex]

Step-by-step explanation:

volume of bottom: 6 x 10 x 5 = 300 [tex]cm^3[/tex]

volume of top:

[tex]V = (\frac{4}{3}\pi r^3)/2\\\\= (\frac{4}{3}\pi(4)^3)/2\\[/tex]

≈ 134.041 [tex]cm^3[/tex]

300 + 134.041 = 434.041

they want to the nearest tenth, so it would just be 434.0

Answer:

90%

Step-by-step explanation:

9514 1404 393

Answer:

  1.3

Step-by-step explanation:

The two points are on the same vertical line, so the distance between them is the distance between their y-coordinates:

  2.5 -1.2 = 1.3

The distance between the two points is 1.3 units.

Answer:

D.7

Step-by-step explanation:

[tex] 4 - ( - 3) = 4 + 3(because \: - \times - ) \: it \: is \: positive \\ = 7[/tex]

Answer:

I think 7

Step-by-step explanation:

if the moon is purple then what toothpaste do u use on your but

Answer:

Arithmetic Sequence

Step-by-step explanation:

In Arithmetic sequence each term increases by adding/subtracting some constant k. This is in contrast to a geometric sequence where each term increases by dividing/multiplying some constant k.

Answer:

[tex]=13.6[/tex]

Step-by-step explanation:

[tex]\mathrm{Remove\:parentheses}:\quad \left(a\right)=a[/tex]

[tex]=4\left(3.4+2\right)-\frac{56}{7}[/tex]

[tex]=21.6-8[/tex]

[tex]\mathrm{Subtract\:the\:numbers:}\:21.6-8=13.6[/tex]

[tex]=13.6[/tex]

Answer:If the figure is a square with a perimeter of 16 inches, then each side of the square is 4 inchest in length.

Step-by-step explanation:

Answer:

The length of each side is 4 inches.

Step-by-step explanation:

Since the shape is a square, all sides are equal so you do 16÷4 since there are 4 sides to get your answer of 4 inches.

Answer:

12345678910

Step-by-step explanation:

CHARRRRRRRRR joke lang bestie

Answer:

Electrician = 44

Plumber = 22

Step-by-step explanation:

Let :

Electrician Hourly wage = x

Plumber's hourly wage = y

Average = 33

(x + y ) /2 = 33

x + y = 66 - - - - (1)

7x + 4y = 396 - - - (2)

From (1)

x = 66 - y

Put x = 66 - y in (2)

7(66-y) + 4y = 396

462 - 7y + 4y = 396

-3y = - 66

y = 22

x = 66 - 22

x = 44

Electrician = 44

Plumber = 22

Answer:

The correct answer would be [tex]a=\sqrt{c^2-b^2}[/tex]

Step-by-step explanation:

given [tex]a^2+b^2=c^2[/tex] we want to solve for a

How?

We can do this by using basic algebra ( isolating the variable (a ))

Step 1 subtract [tex]b^2[/tex] from each side

[tex]a^2+b^2-b^2=a^2\\c^2-b^2=c^2-b^2[/tex]

now we have [tex]a^2=c^2-b^2[/tex]

step 2 take the square root of each side

[tex]\sqrt{a^2} =a\\\sqrt{c^2-b^2} =\sqrt{c^2-b^2}[/tex]

we're left with [tex]a=\sqrt{c^2-b^2}[/tex]

Hence your answer is A

Answer:

-4 + 6°

Step-by-step explanation:

- (8 - 12) + 6° + (- 4)2 = - ( - 4) + 6° - 8 = 4 + 6° - 8 = - 4 + 6°

Answer:

(3x+5)+(2x) = 90

5x + 5 = 90

5x = 85

x = 17

YVZ = 3×17 +5

=56°

Answer:

The first thing we need to do is to find the area bounded by:

y = x^3

y = 0

between:

x = 0 and x = 2

This is the integral of the given function between x = 0 and x = 2, written as:

[tex]\int\limits^2_0 {x^3} \, dx = \frac{2^4}{4} - \frac{0^4}{4} = 2^2 = 4[/tex]

This means that the area of the bounded region is 4 square units.

Now, if we do a full rotation around the x-axis, the volume generated will be equal to the area that we obtained times 2*pi units.

The volume is:

V = (4 square units)*(2*pi units) = 8*pi cubic units.

(Notice that no option coincides with this, there may be a mistake in the options)

height of movable brigde 37cm

width of movable brigde 85 cm