A consumer group is testing camp stoves. To test the heating capacity of a stove, they measure the time required to bring 2 quarts of water from 50 degrees to boiling.
Two competing models are under consideration. Thirty-six stoves of each model were tested and the following results were obtained.
Model 1: mean time is 11.4 and standard deviation is2.5
Model 2: mean time is 9.9 and standard deviation is 3.0
Is there any difference between the performances of these two models? {use a .05 level of significance}. Find the p-value of the sample statistic and do a significance test.
Find a 95% confidence interval for the difference of the means.

Answers

Answer 1

Answer:

a

The decision rule  is  

Reject the null hypothesis

  The conclusion is  

There is sufficient evidence to show that there is a difference between the performances of these two models

b

The  95% confidence interval is  [tex] 0.224   <  \mu_1 - \mu_2  < 2.776  [/tex]

Step-by-step explanation:

From the question we are told that

    The sample size is  n  =  36

    The first sample mean is  [tex]\= x_1 = 11.4[/tex]

    The first standard deviation is  [tex]s_1 = 2.5[/tex]

    The second sample mean is   [tex]\= x_2 = 9.9[/tex]

     The second standard deviation is  [tex]s_2 = 3.0[/tex]

      The level of significance is  [tex]\alpha = 0.05[/tex]

The null hypothesis is  [tex]H_o : \mu_1 - \mu_2 = 0[/tex]

The alternative hypothesis is [tex]H_a : \mu_1 - \mu_2 \ne 0[/tex]

Generally the test statistics is mathematically represented as

      [tex]z = \frac{ (\= x_1 - \= x_2 ) - (\mu_1 - \mu_2 ) }{ \sqrt{ \frac{s_1^2 }{n} + \frac{s_2^2 }{ n} } }[/tex]

=>    [tex]z = \frac{ ( 11.4 - 9.9) - 0 }{ \sqrt{ \frac{2.5^2 }{36} + \frac{ 3^2 }{36 } } }[/tex]

=>     [tex]z = 2.3[/tex]

From the z table  the area under the normal curve to the left corresponding to  2.3 is  

       [tex]P( Z > 2.3 ) = 0.010724[/tex]

Generally the p-value is mathematically represented as

      [tex]p-value = 2 * P( Z > 2.3 )[/tex]

=>    [tex]p-value = 2 * 0.010724[/tex]

=>    [tex]p-value = 0.02[/tex]

From the value obtained we see that  [tex]p-value < \alpha[/tex] hence  

The decision rule  is  

Reject the null hypothesis

  The conclusion is  

There is sufficient evidence to show that there is a difference between the performances of these two models

Considering question b

From the question we are told the confidence level is  95% , hence the level of significance is    

      [tex]\alpha = (100 - 95 ) \%[/tex]

=>   [tex]\alpha = 0.05[/tex]

Generally from the normal distribution table the critical value  of  [tex]\frac{\alpha }{2}[/tex] is  

   [tex]Z_{\frac{\alpha }{2} } =  1.96[/tex]

Generally the margin of error is mathematically represented as  

      [tex]E = Z_{\frac{\alpha }{2} } *  \sqrt{ \frac{s_1^2 }{n } + \frac{s_2^2}{n}} [/tex]

 => [tex]E = 1.96  *    \sqrt{ \frac{2.5^2 }{ 36 } + \frac{ 3^2}{36}}  [/tex]

  => [tex]E = 1.276   [/tex]

Generally 95% confidence interval is mathematically represented as  

      [tex]( \= x_1 - \= x_2) -E <  \mu_1 - \mu_2  < ( \= x_1 - \= x_2) + E [/tex]

=>  [tex]( 11.4 - 9.9 ) -1.276  <  \mu_1 - \mu_2 < ( 11.4 - 9.9 ) + 1.276   [/tex]

=>  [tex] 0.224   <  \mu_1 - \mu_2  < 2.776  [/tex]


Related Questions

solve for the missing value (?) 3:9=? ?:81=

Answers

Answer:

27

Step-by-step explanation:

First you need to figure out what times 9 = 81

9 x 9 =81

since you have to do the same thing on both sides of the equation you do

3 x 9

which gets you 27

PLZ HELP ME WITH THIS!!! I WOULD MARK YOU BRAINLIEST!!!

Answers

the answer will be 2.5 hope that helps you

Answer:

2.5 or in other terms 2 1/2

Step-by-step explanation:

If point C lies between two points A and B such that AC=BC, then

Answers

Answer:

If point C lies between two points A and B such that AC=BC, then point C is the bisector of A and B, that means it is at right the centre.

Dreya is saving money to purchase a $900 computer, and she saves $10 the first week. Each week after that, she saves $3 more than the previous week, except in the last week, when she reaches $900. To have a final sum of exactly $900, how much money does Dreya need to save in her final week of saving?
$13
$60
$70
$73

Answers

Answer:

$ 60

Step-by-step explanation:

hope it helps!

.....

Answer:

It is B

Step-by-step explanation:

Got it right on unit review

Lacey is buying a new car. She can get a station wagon, a truck, a hatchback, or a convertible. The outside paint comes in yellow or green. The seats can be covered with white leather or gray fabric. Given these choices, how many different combinations does Lacey have to choose from?

Answers

Step-by-step explanation:

4 different vehicles,

2 different paints,

2 different seats.

Total number of combinations = 4 * 2 * 2 = 16.

HELPPPPP ME PLEASEEEE


the product of 9/10 and 8/9 is...
A: between 0 and 1
B: between 1 and 2
C: between 2 and 3
D: greater than 3

Answers

Between 0 and 1 I think because you have to find common denominators
It would be B: between 1 and 2 because the answer to that is 1.8 (rounded) so it is more than one but less than 2.

if you dont know what 3x4= its 12

Answers

Answer:

thanks im not smart

Step-by-step explanation:

sn i knew that...

Yea you should know that

The rational function f is defined as, where h and g are polynomials.
The degree of h is m and the degree of g is n.
Which of the following statements are TRUE?


I. If m > n the absolute value of the function approaches positive infinity as x gets very large.


II. If m < n the value of the function approaches zero as x gets very large.


III. If m = n the value of the function approaches a constant as x gets very large.

Answers

Answer:

g

Step-by-step explanation:

x goes to f m to 5 :-)

Which of these graphs represents a function?
A)
A
B)
B
C)
С
D)
D

Answers

Do the vertical line test and draw a straight line.

Solution: C represents a function
B represents a function

Jimmy and Chris go to Chick-fill-A. Jimmy orders 2 chicken sandwhiches and 5 cookies and pays
$17. Chris orders 3 chicken sandwiches and 2 cookies and pays $20. How much does a chicken
sandwich cost?

Answers

Answer:

A sandwich costs $6

Find sin θ. Right Triangle Trigonometry.

Answers

Answer:

A. 16/20

General Formulas and Concepts:

Trigonometry

[Right Triangles Only] SOHCAHTOA[Right Triangles Only] sin∅ = opposite over hypotenuse

Step-by-step explanation:

Step 1: Identify

Angle θ

Opposite Leg = 16

Hypotenuse = 20

Step 2: Find Ratio

Substitute [Sine]:                    sinθ = 16/20

Answer:

A. 16/20

Step-by-step explanation:

The sine ratio is the opposite leg over the hypotenuse, opp/hyp.

For angle theta, the opposite leg is 16. The hypotenuse is 20.

sin (theta) = 16/20

Answer: A. 16/20

evaluate each expression |-16| - |4|

Answers

The answer would be 12 as the absolute value makes it positive for the inside number and then 16-4 is 12

The lines A and B are parallel. Identify a pair of corresponding angles?

Answers

Answer:

2 and 5............................

Answer:

Yes. 2 & 5 / 4 & 8 / 1 & 6 / 3 & 7 (Choose one yourself)

Step-by-step explanation:

Corresponding angles are angles that have one angle outside a pair of parallel lines and one angle within it and they are equal to each other.

The highest recorded temperature in the world is 120°F. The lowest recorded temperature in the world is -129.6°F. What is the difference in the two temperatures?



Group of answer choices

9.6 degrees

29.6 degrees

229.6 degrees

249.6

Answers

Answer: 249.6 degrees

Explanation: When you see the subtraction symbol followed by a negative symbol, turn the two signs into a plus sign. As a result, the problem turns into a simple addition problem.

120 + 129.6 = 249.6

simplify x^2 + ax - 2a^2÷
3a^2 - 2ax - x^2?

Answers

Answer:

[tex] - \frac{x + 2a}{3a + x} [/tex]

Step-by-step explanation:

[tex] \frac{ {x + ax - 2 {a}}^{2} }{3a {}^{2} - 2ax - {x}^{2} } [/tex]

i) write ax as a difference

[tex] \frac{ {x}^{2} + 2ax - ax - 2 {a}^{2} }{3 {a}^{2} - 2ax - x {}^{2} } [/tex]

ii) write -2ax as a difference

[tex] \frac{ {x}^{2} + 2ax - ax - 2a {}^{2} }{3a {}^{2} + ax - 3ax - x {}^{2} } [/tex]

iii) factor out x from the expression

[tex] \frac{x(x + 2a) - ax - 2 {a}^{2} }{3 {a}^{2} + ax - 3ax - {x}^{2} } [/tex]

iv) factor out -a from the expression

[tex] \frac{x(x + 2a) - a(x + 2a)}{3 {a}^{2} + ax - 3ax - {x}^{2} } [/tex]

v) factor out a from the expression

[tex] \frac{x(x + 2a) - a(x + 2a)}{a(3a + x) - 3ax - {x}^{2} } [/tex]

vi) factor out -x from the expression

[tex] \frac{x(x + 2a) - a(x + 2a)}{a(3a + x) - x(3a + x)} [/tex]

vii) factor out x+2a from the expression

[tex] \frac{(x + 2a)(x - a)}{a(3a + x) - x(3a + x)} [/tex]

viii) factor out 3a+x from the expression

[tex] \frac{(x + 2a)(x - a)}{(3a + x)(a - x)} [/tex]

ix) factor out the negative sign from the expression and rearrange the term

[tex] \frac{(x + 2a)( - ( - a - x))}{(3a + x)(a - x)} [/tex]

x) reduce the fraction a-x

[tex] \frac{(x + 2a)( - 1)}{(3a + x)} [/tex]

[tex] - \frac{x + 2a}{3a + x} [/tex]

16 > 2y - 4 solve for y ​

Answers

Answer: y<10

Step-by-step explanation:

2y<16+4

2y<20

y<10

Answer:

Step-by-step explanation:

Simplifying

16 = 2y + -4

Reorder the terms:

16 = -4 + 2y

Solving

16 = -4 + 2y

Solving for variable 'y'.

Move all terms containing y to the left, all other terms to the right.

Add '-2y' to each side of the equation.

16 + -2y = -4 + 2y + -2y

Combine like terms: 2y + -2y = 0

16 + -2y = -4 + 0

16 + -2y = -4

Add '-16' to each side of the equation.

16 + -16 + -2y = -4 + -16

Combine like terms: 16 + -16 = 0

0 + -2y = -4 + -16

-2y = -4 + -16

Combine like terms: -4 + -16 = -20

-2y = -20

Divide each side by '-2'.

y = 10

Simplifying

y = 10

What is 3/5 converted into a percent.

Answers

Answer:

60%

Step-by-step explanation:

multiply 3/5 by 20

Answer:

60%

since 100/100 is 100%, we just have to find a number that will make the denominator 5 equal to 100. That is 20 so we multiply 20 for both 3 and 5. This equals to 60/100, which is 60%

What is the GCF of the expression -x2y22 - xy2z?​

Answers

Answer:

i dont onderstand Thais

Please help me out !!!

Answers

Answer:

If the segments AU and UT are equal then AT equals 66, if the segments are not equal then AT equals 6x+24. Depends on what you are learning. Use what you need!

Step-by-step explanation:

4x+5 = 2x+19

2x=14

x=7

4(7)+5+2(7)+19 = 42+24 = 66

Identify the graph that displays the speed of a car accelerating onto a highway until it reaches the speed limit, and then continuing on the highway at the speed limit. ​

Answers

Answer: D

Step-by-step explanation:

Graph D shows the car increasing speed over time, then, the flat line shows the car remains at a constant speed. In order for the scenario to apply, there needs to be a line parallel to the x-axis which shows a speed remaining the same over a given amount of time. D is the only graph which has this feature, thus this graph displays the scenario.

I WILL GIVE BRAINLIEST!!!

Answers

Answer: m = 4

Step-by-step explanation:

h(n)=3n-4 find h(-6)

Answers

Answer:

h(-6) = -22

Step-by-step explanation:

h(n) = 3n - 4

h(-6)= 3(-6) - 4

= -18 - 4

= -22

I need help what r these coin?​

Answers

Answer:

those are called quarters

Answer:

Well Caden has 3 quarters (which . 75 cents since they are .25 cents a piece ), he also has a dime, (which is .10 cents ) and also a nickel. ( which is .5 cents)

Caden: .75+.10+.5= $1.00

Eden has a quarter (.25 cents), 2 dimes (.20 cents) and 2 nickels ( .10 cents )

Eden : .25+.20+.10= .55 cents

Harper has 2 quarters (.50 cents), 2 dimes ( .20 cents) and 2 nickels( .10 cents)

Haper: .50+.20+.10= .80cent s

Step-by-step explanation:

I hope this helps and if it does please mark me the brainliest! Peace and love

Evaluate the limit, if it exists. PLEASE SHOW WORK
lim x 5 x^2-3x-10\2x-10

Answers

Answer:

-350

Step-by-step explanation:

5×2-3×-10/2×-10

=10-3×-50

=7×-50

=-350

yall the answer is 0.17 hope this help

Answers

Answer:

I just saw a girl post the nastiest nu!des EVER

What is the area of the trapezoid.

Answers

Answer:

60

Step-by-step explanation:

base times height

In a class 3/4 of the boys like math, 1/2 like science, 1/4 of those who like science do not like math. How many boys like neither math nor science?
A. 1/4
B. 1/6
C. 1/2
D. 1/8​

Answers

Brainiest Answer:
D.1/8

Haya la integral de xarcsenx/((1-x^2)^1/2). Utiliza la sustitución de t= arcsenx
Mi duda está la final, cuando queda - tcost + sent + k, no sé cómo sustituir t= arcsent

Answers

Answer:

Explicación más abajo

Step-by-step explanation:

Integración Indefinida

La integral

[tex]I=\int \dfrac{x .arcsen\left(x\right)}{\sqrt{1-x^2}}[/tex]

Se resuelve con el cambio de variables:

t=arcsen(x)

Una vez hechos los cambios, la integral se resuelve en función de t:

[tex]I=sen(t)-t.cos(t)+C[/tex]

Hay que devolver los cambios para mostrarla en función de x.

El cambio de variables también se puede escribir:

x=sen(t)

Recordando que

[tex]cos(t)=\sqrt{1-sen^2(t)}[/tex]

Entonces:

[tex]cos(t)=\sqrt{1-x^2}[/tex]

Devolviendo los cambios:

[tex]I=sen(t)-t.cos(t)+C=x-arcsen(x)\sqrt{1-x^2}+C[/tex]

Es la respuesta correcta

(8.03 LC)
Aaron collects 54 rocks at the beach. He wants to give an equal number of rocks to 6 of
his friends. How many rocks did each of Aaron's friends get?
If r represents the number of rocks each friend will get, which equation could be used to
solve the problem?

Answers

r = 9 in the equation r(6) = 54. You would divide by 6 on both sides to have r by itself giving you r = 9

Answer:

9, 54=6r

Step-by-step explanation:

54/6=9 rocks

54=6r

There are 5 students in Mrs. Templeton's art class. Each student has 2 paintbrushes on his desk. Which of the following shows how to find the total number of paintbrushes in the classroom?

Answers

You would have 5 students and you would give them 2 paint brushes each and that would give you 10 because 5x2=10
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