25 scores from all of the students who took the test. She sees that the mean score is 134 with a standard deviation of 6.0547. The superintendant wants to know if the standard deviation has changed this year. Previously, the population standard deviation was 13. Is there evidence that the standard deviation of test scores has decreas

Answers

Answer 1

Answer:

WE fail to reject the Null and conclude that ; Standard deviation of test hasn't decreased.

Step-by-step explanation:

The hypothesis :

H0 : σ = 13

H1 : σ < 13

Using the Chisquare Square statistic :

χ² = (n-1)*s²/σ²

Sample size, n = 25

s² = 6.0547²

σ² = 13²

χ² = (25 - 1)*6.0547² / 13²

χ² = 879.82541016 / 169

χ² = 5.206

The degree of freedom, df = 25 - 1 = 24

The Pvalue(5.206, 24) = 0.99981

Reject H0, if Pvalue < α ;

Since Pvalue > α ; WE fail to reject the Null and conclude that ; Standard deviation of test hasn't decreased.


Related Questions

Let S be a sample of size 31 from a normally distributed population Omega . It is given that the average of the data in S is 120 and the standard deviation is 18. Construct a 90% confidence interval [a, b] for the population mean based on the data in the sample.

Answers

Answer:

48 NO seña hfjxsmisns sisbxbd

Step-by-step explanation:

nzhejsbxbddndbhwksdyanvxydjd4mnnneknwnennnnnn

Domain and range of g(x)= 5x-3/2x+1
Solve for domain and range?

Answers

The domain and the range

The final price of the textbook for an English literature course is 13.5% more than the listed price when tax and shipping costs are included. If the listed price is $147, what is the final price of the textbook?

(Round to the nearest dollar.)

Answers

Answer:

The final price of the textbook rounded to the nearest dollar is $167

Step-by-step explanation:

To solve this problem, we need to find out what 13.5% of $147 equals.

13.5% = 0.135

0.135 x $147 = $19.845

$147 + 19.845 = 166.845

Round to the nearest dollar to get $167

The mean gross annual incomes of certified welders are normally distributed with the mean of $20,000 and a standard deviation of $2,000. The ship building association wishes to find out whether their welders earn more or less than $20,000 annually. The alternate hypothesis is that the mean is not $20,000.

Required:
What is the alternate hypothesis?

Answers

Answer:

H1 : μ ≠ 20000

Step-by-step explanation:

Given that :

Population mean salary, μ = 20,000

To test if mean salary is more or less Than population mean salary, μ, this means we are testing if the mean salary is different from 20,000

Hence, the hypothesis :

Null, H0 : The mean salary is 20000

Alternative, H1 : The mean salary is not 20000

Using notation :

H0 : μ = 20000

H1 : μ ≠ 20000

Hence, alternative hypothesis is : H1 : μ ≠ 20000

Please help!!!!

CE is tangent to this circle, CD is a radius and ECB=48 what is BAC​

Answers

Answer:

48degrees

Step-by-step explanation:

From the circle geometry shown, traingle BDC is an isosceles triangle which shows means that their base angels are the same. Hence;

<B = <C

<CBD + <BCD + <D = 180

<BCD + <BCD + <D =180

2<BCD + <BDC = 180

Get <BCD;

<BCD+ <ECB = 90

<BCD + 48 = 90

<BCD = 90 - 48

<BCD = 42degrees

Get <BDC

2<BCD + <BDC = 180

2(42)+ <BDC = 180

84 + <BDC = 180

<BDC = 180 - 84

<BDC = 96

Since angle at the centre is twice that at the circumference, then;

<BAC = 1/2(<BDC )

<BAC = 96/2

<BAC = 48degrees

pls help! I need the answer quickly! thank you!

Answers

Answer:

B) 36

BA=CD

BA=9

AREA OF TRIANGLE ABC=1/2×b×h

63=1/2×b×9

126=b×9

b=14

BC=14

AD=BC

AE+ED=BC

AE=BC-ED

AE=14-6

AE=8

AREA OF TRIANGLE ACE= 1/2×AE×CD

= 1/2×8×9

=36

Drag each label to the correct location on the table. Each label can be used more than once. Match the attributes to the quadratic functions. x-intercept (-2,0) 1 y-intercept: 0,-8) minimum value: -1 axis of symmetry: 1 x-intercept: 2,0) y-intercept: (0,8) f(x) = x2 - 2x - 8 g(x) = x2 + 6x + 8 h(x) = -x2 + 2x​

Answers

9514 1404 393

Answer:

f: x-intercept (-2, 0), y-intercept (0, -8), axis of symmetry x = 1g: x-intercept (-2, 0), y-intercept (0, 8), minimum value -1h: axis of symmetry x = 1

Step-by-step explanation:

The equations can be written in factored form and vertex form to see the x-intercepts, axis of symmetry, and extreme value.

The y-intercept is the constant in the equation in standard form.

The axis of symmetry is the vertical line through the vertex.

__

f(x)

f(x) = x² -2x -8 = (x -4)(x +2) = (x -1)² -9

  x-intercept (-2, 0), y-intercept (0, -8), axis of symmetry x = 1

__

g(x)

g(x) = x² +6x +8 = (x +2)(x +4) = (x +3)² -1

  x-intercept (-2, 0), y-intercept (0, 8), minimum value -1

__

h(x)

h(x) = -x² +2x = -(x)(x -2) = -(x -1)² +1

  axis of symmetry x = 1

_____

Additional comment

We have only listed the intercepts, axis, and extreme where the values match a label.

Use the point-slope form from the previous question and fill-in the following table of values.

The point-slope equation went through the following 2 points: (0, -1) and (1, 2)

(0, -1)

(1, 2)

(2, )

(3, )

Answers

Answer:

Step-by-step explanation:

Slope of line through (0,-1) and (1,2) = (-1 - 2)/(0 - 1) = 3

Point-slope equation for line of slope 3 that passes through (0,-1):

y+1 = 3(x-0)

When x = 2:

y+1 = 3(2-0)

y = 3·2 - 1 = 5

When x = 3:

y+1 = 3(3-0)

y = 3·3-1 = 8

Erica’s family is moving away from California. They decided to have a moving sale and sell each item for 70% off the price they originally paid for it. The sofa had an original price of $799, and the love seat had an original price of $549. What is the total cost of both items after the discount?

Answers

Find the sale price by multiplying the original price by 70% then add the two prices together to get the total.

799 x 0.70 = 559.30

549 x 0.70 = 384.30

Total: 559.30 + 384.30 = $943.60

The number formed by adding 1 to the greatest 8 – digit number is?

Answers

Answer:

the answer would be 100,000,000

Greatest 8 Digit Number: 99,999,999

Adding 1 = 99999999+1

= 100,000,000

Must click thanks and mark brainliest

Write the expression as a single trigonometric function.
cos 5x cos 6x- sin 5x sin 6x

Answers

Answer:

[tex]\cos(11x)[/tex]

Step-by-step explanation:

Given

[tex]\cos 5x\ \cos 6x- \sin\ 5x \sin 6x[/tex]

Required

Express as a single function

In trigonometry, we have:

[tex]\cos(A + B) = \cos A\cos B - \sin A \sin B[/tex]

By comparison, we have

[tex]\cos(5x + 6x) = \cos 5x\cos 6x - \sin 5x \sin 6x[/tex]

[tex]\cos(11x) = \cos 5x\cos 6x - \sin 5x \sin 6x[/tex]

The mass varies directly as the Kinetic energy (K) and inversely as the square of the velocity (V). if the kinetic energy is 80 Joules and the velocity is 4 meters per second, then the mass is 10 kilograms. Express the mass as a function of kinetic energy and velocity.

Answers

Answer:

m = [tex]\frac{2K}{v^2}[/tex]

Step-by-step explanation:

Given mass (m ) varies directly as K and inversely as v² then the equation relating them is

m = [tex]\frac{kK}{v^2}[/tex] ← k is the constant of variation

To find k use the condition m = 10 when K = 80 and v = 4 , then

10 = [tex]\frac{80k}{4^2}[/tex] = [tex]\frac{80k}{16}[/tex] ( multiply both sides by 16 to clear the fraction )

160 = 80k ( divide both sides by 80 )

2 = k

m = [tex]\frac{2K}{v^2}[/tex] ← equation of variation

The expression of mass as a function of kinetic energy and velocity is m = 2K/V².

What is an expression?

Expressions are defined as mathematical statements that have a minimum of two terms containing variables or numbers.

We have been given that the mass varies directly as the Kinetic energy (K) and inversely as the square of the velocity (V).

m ∝ K/V²

m = cK/V²

Here c is the constant of variation,

If the kinetic energy is 80 Joules and the velocity is 4 meters per second, then the mass is 10 kilograms.

We have to determine the value of c

Here m = 10 , K = 80 and V = 4 , then

Substitute the values in m =  cK/V²

10 = c(80)/4²

10 = c(80)/16

10 = 5c

c = 10/5

c = 2

Substitute the value of c = 2 in the equation of variation,

⇒ m = 2K/V²

Hence, the expression of mass as a function of kinetic energy and velocity is m = 2K/V².

Learn more about the expressions here:

brainly.com/question/13947055

#SPJ2

1. Find the volume of the shipping box using the two methods and show your work plzzzzzzzz i neeeeeeeeeeeeeed help

Answers

Step-by-step explanation:

Measure the width, length and height of the shipping box in inches. Multiply the width, length and height of the box to calculate its volume in cubic inches. For example, if the box is 20 inches wide, 24 inches long and 16 inches high, then the volume is (20)(24)(16) = 7,680 cubic

Answer:

The volume of the shipping box would be 36 9/16

Step-by-step explanation:

One method to find the volume of the shipping box would be (l)(w)(h)

one we plug in our dimensions the equation would become 3 1/4 x 3 x 3 3/4

To simplify this we would first

Multiply

3 1/4 x 3 x 3 3/4 = 39/4 x 3 3/4

The bolded parts are the pieces we are working on

3 1/4 as an improper fraction is 13/4

13/4 x 3 = 13 x 3/4 = 39/4

- The second step would be to

Convert the mixed number to an improper fraction.

3 3/4  = ( 3 × 4 ) / 4 + 3/4 = 12 + 3 / 4 = 15/4

Now we have to Multiply

39/4 x 15/4 =  39 x 15 / 4 x 4 = 585/16

Lastly, we have to simplify

585/16 = 36 9/16

what is the smallest number to be subtracted from 9610,so that the remainder will be a perfect square​

Answers

Answer:

Hello,

Answer 6

Step-by-step explanation:

[tex]\sqrt{9610} =98,03060...\\\\ENT(\sqrt{9610})=98\\\\9610-98^2=9610-9604=6\\\\[/tex]

The smallest number to be susbtracted is 6

Một đài khí tượng thủy văn muốn xem xét khả năng dự báo thời tiết của mình. Từ số liệu thống kê chỉ ra rằng: xác suất dự báo có nắng trong ngày không mưa là 0,95; có nắng trong ngày mưa là 0,8; xác suất một ngày sẽ không mưa là 0,6. a. Tính xác suất dự báo ngày sẽ có nắng. b. Biết đã có dự báo là ngày có nắng, tính xác suất để ngày đó là ngày không mưa.

Answers

Answer:

ask in English then I can help u

A region c
B region d
C region a
D region b

Answers

Answer:

Region C

Step-by-step explanation:

y ≤ ¼ x + 3 maps the areas C and D including the common boundary line

y ≥ -x + 5 maps the areas B and C including the common boundary line

The common area mapped is C plus its boundaries

A $22,000 loan was taken out. If $24,805 is due at the end of the loan after being compounded daily at 2.5%, how many
years was the loan for? (Round to the nearest tenth of a year)
Provide your answer below

Answers

9514 1404 393

Answer:

  4.8 years

Step-by-step explanation:

Solving the compound interest formula for the number of years gives ...

  t = log(A/P)/(n·log(1 +r/n))

where principal P invested at rate r compounded n times per year produces value A after t years.

  t = log(24805/22000)/(365·log(1 +0.025/365)) ≈ 4.800

The loan was for 4.8 years.

What is the probability of throwing a total score of 10 or less with two dice?​

Answers

hope it helps

please mark Brainliest

PLEASE HELP LOOK AT PICTURE

Answers

the answer is option 2. try subbing in the values of each of the X values and you’ll discover that option 2 is correct since the answers match with the Y values

Based on a random sample of 50, a 95% confidence interval for the population proportion was computed. Holding everything else constant, which of the following will reduce the length of the confidence interval by half? (CHECK ALL THAT APPLY): A. Quadruple the sample size. B. Change the confidence level to 68%. C. Double the sample size. D. Change the confidence level to 99.7%. E. Decrease the sample proportion by half.

Answers

The length of the confidence interval is the margin of error, which is the ratio of the standard deviation and the square root of sample size. Hence, to reduce the length of confidence interval by half, Quadruple the sample size.

Recall :

Margin of Error = σ/√n

Evaluating an hypothetical scenario :

Let standard deviation, σ = 2

Sample size = 50

Margin of Error = 2/√50 = 0.554

Using Quadruple of the sample size : (50 × 4) = 200 samples

Margin of Error = 2/√200 = 0.277

(0.227 ÷ 0.554) = 0.5

Therefore, increasing the sample size, reduces the margin of error. Hence, using quadruple the sample size, will reduce the margin of error by half.

Learn more : https://brainly.com/question/13403969

what is the tan invers of 3i/-1-i​

Answers

z = 3i / (-1 - i )

z = 3i / (-1 - i ) × (-1 + i ) / (-1 + i )

z = (3i × (-1 + i )) / ((-1)² - i ²)

z = (-3i + 3i ²) / ((-1)² - i ²)

z = (-3 - 3i ) / (1 - (-1))

z = (-3 - 3i ) / 2

Note that this number lies in the third quadrant of the complex plane, where both Re(z) and Im(z) are negative. But arctan only returns angles between -π/2 and π/2. So we have

arg(z) = arctan((-3/2)/(-3/2)) - π

arg(z) = arctan(1) - π

arg(z) = π/4 - π

arg(z) = -3π/4

where I'm taking arg(z) to have a range of -π < arg(z) ≤ π.

factor the expression completely. -30+36x

Answers

Answer:

6 (-5 + 6x)

Step-by-step explanation:

Rewrite the number 30 as 6×5 and 36 as 6×6

Factor out the common number, which is 6

so, 6 (-5 + 6x)

Answer:

-6(5-6x).

Just factor out -6 from the expression. Thank you!

Dylan has a coworker who is always showing up late and then not finishing his work on time. It's frustrating the other members of the team. What can he do that might help the situation? a) Complain about the coworker to other team members O b) Ask his coworker if he understands his job responsibilities c) Tell his boss that the coworker is slacking off O d) Complete his coworker's work for him

Answers

the answer is bbbbb ask his co worker if he understands his job responsibilities

help with math it would help with summer school

Answers

Answer:

[tex]A). \ \ \frac{(72\pi + 9\pi )}{4} \ in^2[/tex]

Step-by-step explanation:

Given;

radius of the circle, r = 9 inches

the part of the circle cut out = one-forth of the complete circle

the angle of the sector cut out θ= ¹/₄ x 360 = 90⁰

Area of the complete circle = πr² = π x 9² = 81π in²

Area of the sector cut out = [tex]= \frac{\theta }{360} \pi r^2 = \frac{90}{360} \pi (9^2) = \frac{1}{4} \times 81\pi = \frac{81 \pi}{4} = \frac{(72\pi + 9\pi)}{4} \ in^2[/tex]

Therefore, the only correct option is A. [tex]\frac{(72\pi + 9\pi )}{4} \ in^2[/tex]

Which of the relations given by the following sets of ordered pairs is a function?
o {(5,2), ( - 4, 2), (3,6), (0,4), (- 1, 2)}
o {(5, 4), (5, 6), (5,8), (5, 10), (5, 12)}
{(-3, - 2), ( - 2, – 1), (0, - 1), (0, 1), (1, 2)}
{(7,3), ( – 6,8), ( – 3,5), (0, – 3), (7, 11)}

Answers

9514 1404 393

Answer:

  (a)  {(5, 2), (-4, 2), (3, 6), (0, 4), (-1, 2)}

Step-by-step explanation:

The only relation with no repeated x-values is the first one. The first relation is a function.

The fuel efficiency of a vehicle is 28 miles per gallon and gasoline cost 2.25 per gallon. What is the cost per mile to drive the vehicle?​

Answers

Answer:

$.08 per mile

Step-by-step explanation:

$2.25          gallon

------------ * ---------------

gallon          28 miles

$2.25

-------------

28 miles

$.080357143 per mile

Rounding to the nearest cent

$.08 per mile

Find the area of a triangle with legs that are: 12 m, 15 m, and 9 m.

Answers

Answer:

108 meters squared or m^2

Step-by-step explanation:

* means multiply

15 is probably hypotenuse because its the longest

12 and 9 are probably base and height

area = base * height

area = 12 * 9

area = 108

Answer:

54m^2

Step-by-step explanation:

if Albert gives 30$ to George both of them will have the same amount of money.if George give 50$ to Albert,Albert will have 5 times as much money as George. how much money do both of them have altogether​

Answers

Step-by-step explanation:

let George money will be X and Albert be Y

30$+x=y

x-50$=5y

30+x=y

x=y-30

(y-30)-50=5y

y-80=5y

y-5y=80

-4y=80

y=-20

x=-50

Answer:AlBERT=150; GEORGE=90

Albert-30=George+30....(.1)eq

A=(G+60)

#2 (G-50)5=A+50......(.2)eq

substitute result of #1 for A

5G-250=(G+60)+50

4G=360

G=90

substitute $90 into equation #1

A=90+60=150

Therefore Albert has $150, George has $90, and their total is $240

Find the x- and y-intercept of the line
X+4y=36

Answers

the answer:
(36,0) (0,9)

If (x^2−1)/(x+1) = 3x + 5, then x + 3 =
(A) -3
(B) -2
(C) 0
(D) 2
(E) 4

Answers

The answer is C) 0
Because math
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