n automobile manufacturer claims that its van has a 37.4 miles/gallon (MPG) rating. An independent testing firm has been contracted to test the MPG for this van since it is believed that the van has an incorrect manufacturer's MPG rating. After testing 280 vans, they found a mean MPG of 37.8. Assume the standard deviation is known to be 2.3. A level of significance of 0.05 will be used. Find the value of the test statistic. Round your answer to 2 decimal places.

Answers

Answer 1

Answer:

Then z(s) is out of the acceptance region, we reject H₀,  doubts of the independent testing firm are valids

Step-by-step explanation:

We will develop a Hypothesis Test ( a 2 tail test since the independent testing firm is interested in finding out  if there is an incorrect MPG rating from the manufacturer

Test Hypothesis :

Null hypothesis                             H₀            μ    =    μ₀

Alternative Hypothesis                Hₐ             μ    ≠    μ₀

Significance Level   α  = 0,05    α/2  =  0,025

z(c) for α/2   from z-table      z(c)  = - 1, 96   and by symmetry  z(c) = 1,96

Calculating  z(s)

z(s) =  ( μ  -  μ₀ ) / σ /√n

z(s) = ( 37,8 - 37,4 ) / 2,3 /√280

z(s) = 0,4 * 16,73 / 2,3

z(s) = 2,90

Comparison between z(c)  and  z(s)

z(s) > z(c)       2,90 > 1,96

Then z(s) is out of the acceptance region, we reject H₀,  doubts of the independent testing firm are valids


Related Questions

A shoe company wants to test an updated model of a running shoe on its wear after one month of running. They recruit 50 people who run on a regular basis to participate in the study. Twenty-five runners will receive a pair of the new model and the remaining 25 will receive a pair of the current model. After one month, the wear on the shoes will be determined using the depth of the tread and the flexibility of the toe box. The wear between the new and current models will then be compared.

Which of the following describes a completely randomized design for this experiment?

The subjects are numbered 1–50 and these numbers are put into a random number generator. The first 25 random numbers, ignoring repeats, represent the subjects assigned to the new model group. The remaining 25 subjects will wear the current model.
The subjects’ names are written on equal-sized slips of paper and placed into a hat. A researcher then reaches in and pulls out 25 slips of paper. These subjects are assigned to the new model group. The remaining 25 subjects will be assigned to the current model group.
The 50 subjects are paired based on running ability. The fastest two runners are paired together, the next fastest, etc. For each pair of runners, the researcher will flip a coin. If the coin lands on heads, the first runner will receive the new model and the second runner will receive the original model.
The 50 subjects are grouped based on running ability. Twenty runners classify themselves as competitive runners and the remaining 30 classify themselves as recreational runners. For the competitive group, the runners’ names are written on equal-sized slips of paper and placed into a hat. The slips are shuffled, and the first 10 runners wear the new model and the other 10 wear the current model. The same procedure is used to assign the shoes to the recreational group.

Answers

Answer:

Option A: The subjects are numbered 1–50 and these numbers are put into a random number generator. The first 25 random numbers, ignoring repeats, represent the subjects assigned to the new model group. The remaining 25 subjects will wear the current model.

Step-by-step explanation:

We are told that Twenty - five runners will receive a pair of the new model and the remaining 25 will receive a pair of the current model.

Now, a completely randomized design is defined as one where the treatments will be assigned completely at random in such a manner that each experimental unit will posses the same chance of receiving any of the treatments given.

To this effect, the most likely answer will be picking people at random to assign either the new model or current model.

This is usually done by making a list of the treatment combinations and then assigning a random number to each subject.

Looking at the options, the most appropriate will be option A.

Help please !!!
A. 90
B. 45
C. 0
D. 1

Answers

Answer: C.0

x + 45 is the angle outside the circle of shield 2 arcs with measurements 55 and 145

=> x + 45 = 1/2.(145 - 55)

⇔ x + 45 = 1/2. 90

⇔ x + 45 = 45

⇔ x = 0

Step-by-step explanation:

A regular hexagon has an area of 750.8cm². The side length is 17cm. Find the apothem.

A. 7.4cm
B. 14.7cm
C. 21.5cm
D. 88.3cm

Answers

The formula for determining the apothem of regular hexagon is s/2tan(180/n) , where 's' is any side length of regular hexagon and 'n' is the number of sides of regular hexagon.
So, apothem = 17/2tan(180/n)
= 17/2tan(30)
= 17/1.15
= 14.78 units
Therefore, the measure of apothem of the regular hexagon is 14.7 units.
B is the right answer.

What is the perimeter of the quadrilateral below?

Answers

Answer:

[tex]\boxed{26}[/tex]

.

Step-by-step explanation:

First step, find the value of tilted line. use pythagoras

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

[tex]c^2 = 3^2 + 4^2[/tex]

[tex]c^2 = 9 + 16[/tex]

[tex]c^2 = 25[/tex]

[tex]c = \sqrt{25}[/tex]

[tex]c = 5[/tex]

.

So, the primeter is

[tex]= 2(5) + 4 + 12[/tex]

[tex]= 26[/tex]

pls help this is not graded ​

Answers

Answer:

70 degrees

Step-by-step explanation:

Its seventy (70) degrees

A group of 4444 friends is playing cards. The deck has 70707070 cards. To start the game, the dealer makes a pile of 15151515 cards in the center. Then she deals the remaining cards one at a time to each player until all the cards are gone.
What is the greatest number of cards any player will have after all the cards are dealt?
cards

Answers

Answer:

12502 cards

Step-by-step explanation:

Given:

» total of 70707070 cards of the deck

» 15151515 cards were taken and put in a pile

Solve:

1. So, you can subtract 15151515 from 70707070 to find how many cards are left:

70707070 - 15151515 = 55555555

2. Now, there are 55555555 cards remaining in the deck since 15151515 cards were taken to put in a pile. Since the dealer deals the remaining cards to 4444 people, you can just do 55555555 divided by 4444 to find how many cards each person gets:

55555555 ÷ 4444 = 12501.25

3. 12501.25 is the exact number of cards each person gets, but you can’t have a fraction/part of a card. You have to find a specific remaining number:

0.25 is the same as [tex]\frac{1}{4}[/tex], and so convert [tex]\frac{1}{4}[/tex] into a fraction with a denominator of 4444, but is still equivalent to [tex]\frac{1}{4}[/tex]: You’ll get [tex]\frac{1111}{4444}[/tex], which is correct because it’s still equivalent to [tex]\frac{1}{4}[/tex]

4. So, the remaining 55555555 cards divided by 4444 people is 12501 cards and a remainder of 1111 cards. The 1111 cards can be distributed upon the players, but not everyone can get it. Since 12501 were to given to the players and after the remaining 1111 were also distributed, this means that some will have 12501 cards and others will have 12502 cards.

Answer: So, the greatest number of cards any player will have after all the cards are dealt is 12502 cards.

does anyone know algebra? if so, I can really use your help.

Answers

Answer:

yea sure

Step-by-step explanation:

Yeah lmk what you need help in

PLEASE HELP IT WOULD MEAN A LOT THX! :(

Answers

I can’t see it at all
The number 1000 in exponential form is 103. This means multiplying 10 three times to get 1000.

what is the distance from the origin to point A graphed on the complex plane below

Answers

Answer:

Coordinates of point A are

(-3,-2)

Origin lies in the center of coordinate system. That means that you can picture this as right triangle with sides 3 and 2 and you need to find hypotenuse of it.

Using pythagoras theorem we calculate:

h^2 = 3^2 + 2^2 = 13

h = sqrt 13

Answer is b

Step-by-step explanation:

Coordinates of point A are

(-3,-2)

Origin lies in the center of coordinate system. That means that you can picture this as right triangle with sides 3 and 2 and you need to find hypotenuse of it.

Using pythagoras theorem we calculate:

h^2 = 3^2 + 2^2 = 13

h = sqrt 13

Answer is b

A right triangle has one angle that measures 24°. What is the measure of the other acute angle?

Answers

Answer:

The measure of the other angle is 66°.

Step-by-step explanation:

Given that the total angles in a triangle is 180° so in order to find the other angles, you have to subtract :

90° + 24° + θ = 360°

114° + θ = 180°

θ = 66°

Salt is poured from a container at 10 cm³ s-¹ and it formed a conical pile whose height at any time is 1/5 the radius of the above. At what rate is the height of the cone increasing when the height is 2 cm form the base of the cone?​

Answers

Given :

Salt is poured from a container at 10 cm³ s-¹ and it formed a conical pile whose height at any time is 1/5 the radius of the above.

To Find :

At what rate is the height of the cone increasing when the height is 2 cm form the base of the cone.

Solution :

We know, volume of a cone is given by :

[tex]V = \dfrac{\pi r^2h}{3}[/tex]

Also, h = r/5

r = 5h

[tex]V = \dfrac{\pi (5h)^2h}{3}\\\\V = \dfrac{\pi 25h^3}{3}[/tex]

Differentiating above equation w.r.t h, we get :

[tex]\dfrac{dV}{dt} = \dfrac{d}{dt}(\dfrac{\pi 25h^3}{3})\\\\\dfrac{dV}{dh} = 25\pi h^2\dfrac{dh}{dt}\\\\\dfrac{dh}{dt}= \dfrac{\dfrac{dV}{dh}}{25\pi h^2 }\\\\\dfrac{dh}{dt}=\dfrac{10}{25\times 3.14\times 2^2}\\\\\dfrac{dh}{dt}=0.032\ cm/s[/tex]

Hence, this is the required solution.

Solve the equation.-7=y/7

Answers

Answer:

y = -49

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right

Equality Properties

Step-by-step explanation:

Step 1: Define

-7 = y/7

Step 2: Solve for y

Multiply 7 on both sides:                    -49 = yRewrite:                                               y = -49

The ratio of boys to girls in 6th grades is 5 to 4. If there are 90 boys, how many girls would there be?

Answers

there would be 17 girls because 90 divided by 5 is 18 and then 18*4=72. please mark me brainliest

prime number between 60 and 80. the tens digit is one less than the ones digit. what is the number​

Answers

Answer:

67

Step-by-step explanation:

The number of prime numbers between the whole numbers 60 to 80 is 5 which are 61, 67, 71, 73, and 79.

What is Algebra?

Algebra is the study of abstract symbols, while logic is the manipulation of all those ideas.

A prime number is a positive integer having exactly two factors which are 1 and the number itself. Any number that does not follow this is termed a composite number.

The prime number between 60 and 80 is given below.

61, 67, 71, 73, and 79

The number of prime numbers between 60 to 80 is 5 which are 61, 67, 71, 73, and 79.

More about the Algebra link is given below.

https://brainly.com/question/953809

#SPJ2

If cos a= 0.93. Sin 0 =0.26, and tan ß = 0.84, find a + B + 0.

Answers

Answer:

77°

Step-by-step explanation:

From the question given above, the following data were obtained:

Cos α = 0.93

Sine θ = 0.26

Tan β = 0.84

α + β + θ =?

Next, we shall determine the value of α. This can be obtained as follow:

Cos α = 0.93

Take the inverse of Cos

α = Cos¯¹ 0.93

α = 22°

Next, we shall determine the value of θ. This can be obtained as follow:

Sine θ = 0.26

Take the inverse of Sine

θ = Sine¯¹ 0.26

θ = 15°

Next, we shall determine the value of β. This can be obtained as follow:

Tan β = 0.84

Take the inverse of Tan.

β = Tan¯¹ 0.84

β = 40°

Finally, we shall determine the value of α + β + θ . This can be obtained as follow:

α = 22°

θ = 15°

β = 40°

α + β + θ = 22 + 40 + 15

α + β + θ = 77°


Which graph has the domain of x>-3? The less than sighn is supposed to have the line under. Will mark the brainliest

Answers

Answer:

Top graph

Step-by-step explanation:

It starts at x and continues right, so x > -3 in that graph

#2) A lifeguard is swimming to a drowning swimmer. The lifeguard's location is at
(0,0) and the swimmer is at (8,5). How far (distance) is the lifeguard from the
swimmer?
9.43
89
6.24
3.61

Answers

Answer:

9.43

Step-by-step explanation:

The formula for calculating the distance between two points is expressed as

D =√(x2-x1)²+(y2-y1)²

Given the coordinates (0,0) and (8,5)

D = √(5-0)²+(8-0)²

D = √5²+8²

D = √25 + 64

D = √89

D = 9.43

Hence the distance between the life guard and the swimmer is 9.43

WILL GIVE BRAINLEIST HELP ASAP (20 points!!)

Answers

hope it helps you pls mark me brainliest pls.

Jovie’s boss tells her to make 6 inch ribbon curls. If she makes 60 ribbon curls per hour, how many hours would it take her to make 480 ribbon curls? Write an equation and then solve.

Answers

Answer:

To make 480 ribbon curls, it would take 8 hours.

Step-by-step explanation:

x=480/60

x=8

Love the Elf reference btw. Hope this helped! :D (Sorry if I'm wrong)


During a trip to the mall, Pam spent $12.95 on a purse, $8.50 for a book, and $3.75 for a smoothie at the food court. She also returned a key chain and received a cash refund of $5.00. If Pam had $24.80 at the end of her trip, how much money did she have initially?

$55.00

$30.20

$37.50

$45.00

Answers

Answer:

The answer is d

Step-by-step explanation:

I used a calculator and i just took away 5.00 from 24.80(which is 19.8) then added all the other numbers to 19.8

In Sam’s art class, 12% of the Flag Day art projects received a perfect score. There were 25 art projects turned in by Sam’s class. How many of the art projects did not earn a perfect score?
need a good answer, lots of details

Answers

Answer:

22 projects did not receive a perfect score

Step-by-step explanation:

12% or 25 is 3, meaning 3 got perfect scores. You would subtract 3 from 25 to get the amount of projects that didnt get a perfect score.

Answer:

52%

Step-by-step explanation:

25 x 4 =100

12 x 4 =48

100-48=52

can someone please answer this i Dont understand ​

Answers

The answer is c.use pemdas❤️

Answer:

C

Step-by-step explanation:

Going by order of PEMDAS (parenthesis, exponents, multiplication, division, addition, subtraction), you add the 2 and the 9 first due to them being in parenthesis. You then multiply by 5.

Write the following numbers in order of size.
Start with the smallest number.
-4
5
0
-2
3

Answers

-4 -2 0 3 5 is the answer

You have received an order for 144 articles. The articles are packed 12 to a box. How many boxes will be needed to fill this order?​

Answers

Answer:

12 boxes will be needed.

Answer:

12 boxes

Step-by-step explanation:

144/12=12

or

1-12x?=144

2-12x10=120

3-12x2=24

4-120+24=144

plsss answer ASAP i really need this fast

Answers

Answer:

650

Step-by-step explanation:

13 into 70 goes 5 times.

5×13=65

13 into 2 goes 0 times.

0×13=0

.•. answer is 650

Answer:702

Step-by-step explanation:

The answer is 254.You see how many time 702 goes into 13 and its 54 .We already have the 50 so there is the 4.

plz answer this within 2 mins and receive brainiest......

Answers

Answer:

Brand B is cheaper by 0.17 per pound.

Step-by-step explanation:

Brand A = 47.7/45 = 1.06

Brand B = 48.95/55 = 0.89

i’m thinking a not sure tho

How do I know if the function is a linear function?

Answers

Answer:

This is not a linear function.

Step-by-step explanation:

It is a quadratic function.  If you were to make a table of the x and y values of the function it would look like this:

x    y

0   -4

1   -1

2    8

Just by looking at these three values, we can see that they do not increase at a consistent rate.  It increases by 3 from 0 to 1, but increase by 9 from 1 to 2.  You can tell if a function is linear by seeing if it increases at a constant rate.  (In this case it does not)

One airplane is at 7,000 feet and is descending 50 feet every second. Another plane is at
1,000 feet and is climbing at a rate of 70 feet per second, How long will it take for the
planes to be at the same heigh

Answers

Given:

One airplane is at 7,000 feet and is descending 50 feet every second.

Another plane is at  1,000 feet and is climbing at a rate of 70 feet per second.

To find:

The time taken by planes to reach at the same height.

Solution:

Let x be the number of seconds after which the planes be at the same height.

One airplane is at 7,000 feet and is descending 50 feet every second.

Change in 1 second = -50 feet   (Here negative sign means decrease)

Change in x second = -50x feet

Height of first airplane after x seconds is

[tex]f(x)=7000-50x[/tex]           ...(i)

Another plane is at  1,000 feet and is climbing at a rate of 70 feet per second.

Change in 1 second = 70 feet

Change in x second = 70x feet

Height of first airplane after x seconds is

[tex]g(x)=1000+70x[/tex]     ...(ii)

Equate (i) and (ii), to find the time after which both planes are on the same height.

[tex]7000-50x=1000+70x[/tex]

[tex]7000-1000=50x+70x[/tex]

[tex]6000=120x[/tex]

Divide both sides by 120.

[tex]50=x[/tex]

Therefore, both planes are at the same height after 50 seconds.

6th grade hw help! Please and ty.

Answers

Answer:  I cant see the pic clearly

Step-by-step explanation:

Answer:

i can't see pic clearly

Add the following complex numbers: (4 - 2i) + (12 + 7i) A. -8 + 5i B. 16 + 5i C. 16 + 9i D. -8 + 9i

Answers

Summing complex numbers is easy: you just sum the real parts together and the imaginary parts together:

[tex](a+bi)+(c+di)=(a+c)+(b+d)i[/tex]

So, you have

[tex](4 - 2i) + (12 + 7i) = (4+12)+(-2+7)i = 16+5i[/tex]

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