A computer manufacturer estimates that its cheapest screens will last less than 2.8 years. A random sample of 61 of these screens has a mean life of 2.4 years. The population is normally distributed with a population standard deviation of 0.88 years. At α=0.02, what type of test is this and can you reject the organization’s claim using the test statistic?

Answers

Answer 1

Answer:

The test is left - tailed

We cannot reject the organization's claim ( its cheapest screens will truly last less than 2.8 years)

Step-by-step explanation:

Sample size, n = 61

Sample mean, [tex]\bar{X} = 2.4[/tex]

Standard deviation, [tex]\sigma = 0.88[/tex]

Significance level,  α=0.02

Null hypothesis, [tex]H_{o} : \mu = 2.8[/tex]

Alternative hypothesis, [tex]H_{a} : \mu < 2.8[/tex]

It is clearly seen from the alternative hypothesis, that it is a left tailed test. It is not tailed towards the two directions.

Calculate the test statistic:

[tex]Z = \frac{\bar{X} - \mu}{\sigma/\sqrt{n} } \\Z = \frac{2.4 - 2.8}{0.88/\sqrt{61} }\\Z = - 3.55[/tex]

Calculate the P-value:

P(Z < -3.35) = 0.0002

Since (p-value = 0.0002) < (α=0.02), the null hypothesis is rejected.

It can therefore be concluded that the mean of the cheapest screen is less than 2.8 years. i.e. the cheapest screen will last less than 2.8 years

Answer 2

Answer:

The null and alternative hypotheses:

H0: u = 2.8

H1: u < 2.8

This is a left - tailed test.

For test statistics, use the formula:

[tex] Z = \frac{x' - u}{\sigma/ \sqrt{n}} [/tex]

Where,

Mean, u = 2.8

Sample mean,x' = 2.4

Sample size, n = 61

Standard deviation [tex] \sigma [/tex] = 0.88

Significance level = 0.02

[tex] Z = \frac{2.4 - 0.02}{0.88/ \sqrt{61}} =-3.55[/tex]

Test statistics, Z = -3.55

Pvalue:

Pvalue of Z = -3.55 using standard normal table,

NORMSTID(-3.55) = 0.00019

Pvalue = 0.0002

Critical value:

Since this is a left tailed test, the critical value at 0.02 level of significance is:

[tex] Z_\alpha = Z_0_._0_2 = -2.05 [/tex]

Decision: If pvalue is less than level of significance reject null hypothesis H0.

Conclusion:

Since pvalue, 0.00019 is less than level of significance, 0.02, reject null hypothesis, H0.

We conclude that the mean life of the cheapest screen is less than 2.8 years


Related Questions

John is selling tickets to an event. Attendees can either buy a general admission ticket, x, or a VIP ticket, y. The general admission tickets are $55 in the VIP tickets are $70. If he knows he sold a total of 25 tickets and made $1480 how many of each type did he sell?

Answers

Answer:

Step-by-step explanation:

55x + 70y = 1480

x + y = 25

55x + 70y = 1480

-55x -55y = -1375

15y = 105

y = 7 VIP tickets sold

x + 7 = 25

x = 18 general admission tickets

(18,7)

Can someone please do the probability please

Answers

Answer:

47/73

Step-by-step explanation:

There are 73 people who like tea. 47 are women, 26 are men. This means that the probabili that the person chosen is a women is 47 out of the 73.

What are the solutions of the system 7x + 3y = -3 and y = -2x? (-1, 0) and (0, -1) (-8, 3) and (3, -8) (-1, 0) and (-8, 3) (0, -1) and (3, -8)

Answers

The solution of the system of equation can be solved by using substitution method. Therefore, the solutions of the system 7x + 3y = -3 and y = -2x is (-3, 6)

How to find solution to the system of equation

7x + 3y = - 3

y = - 2x

Substitute the value of y in equation(i)

Therefore,

7x + 3(- 2x) = -3

7x  - 6x  = -3

x = -3

Let's find y by substituting the value of x in equation(ii)

y = -2x

y = -2(-3)

y = 6

Therefore, the solution set of the equation is (-3, 6)

learn more on system of equation; https://brainly.com/question/1632711

Math help please! What are the possible solutions to this system?

Answers

Answer:

x < 6.5

y < -1.5

Step-by-step explanation:

y > x - 8

Therefore x < y + 8

y < 5 - x

Therefore x < 5 - y

2x < 13

x < 6.5

6.5 < 5 - y

y < -1.5

Alberto sanded a wooden floor with his electric sander at a constant rate. Suppose
1
3
he sanded 40 square feet of floor in hours. How large an area would he have
5
sanded in 1 hour?​

Answers

He would have sanded 30 for 30 hours

When multiplying two negative integers, what is the sign of the product?
positive
negative
zero
one
Mark this and return
Save and Exit
y Next
Sul

Answers

Answer:

positive

Step-by-step explanation:

negative and negative = positive

positive and positive = positive

positive and negative  = negative

negative and positive = negative

hope u got what u needed

Answer:

The correct answer is positive

Step-by-step explanation:

Negitive x Negitive = Positive

Positive x Positive = Positive

Negitive x Postive = Negitive

Positive x Negitive = Negitive

This should help you for next time you have a question like this.

I hope this helps.

The double number lines show the ratio of minutes to days. How many minutes are in 2 days

Answers

Answer:

2880 minutes are in two days

2880 is the answer because you get the minutes of one day and multiple by 2

The price of a vase was increased by 4% to £22. What was the price before the increase? Give your answer to the nearest penny.

Answers

Answer:

The price before the increase was £21.20

Step-by-step explanation:

Now, let the former price before the increment be £x

The increment would be 22-x

Mathematically, the percentage increment = difference between the prices/old price * 100%

Thus, we have(

(22-x)/x * 100 = 4

100(22-x) = 4x

2200-100x = 4x

100x + 4x = 2200

104x = 2200

x = 2200/104

x = 21.154

which is x = 21.2 to the nearest penny

Answer:

21.15

Step-by-step explanation:

22 × 10 = 220

100%+4%=104

104 ÷ 10 = 10.4

220 ÷ 10.4 =21.15384615

To the nearest penny it would be 21.15

Find the third side in simplest radical form

Answers

Answer:    3*sqrt(6)

=========================================================

Work Shown:

We see that one of the legs is unknown. We'll call this 'a'.

The other leg is b = 2, which becomes b^2 = 4

The hypotenuse (always opposite the 90 degree angle) is c = sqrt(58). This turns into c^2 = 58 when you square both sides.

---------

Use the pythagorean theorem to get

a^2+b^2 = c^2

a^2+4 = 58

a^2 = 58-4

a^2 = 54

a = sqrt(54)

a = sqrt(9*6)

a = sqrt(9)*sqrt(6)

a = 3*sqrt(6)

The third side in simplest radical form is x=3[tex]\sqrt{6}[/tex]

RIGHT TRIANGLE

A triangle is classified as a right triangle when it presents one of your angles equal to 90º.  The greatest side of a right triangle is called the hypotenuse. And, the other two sides are called cathetus or legs.

The math tools applied for finding angles or sides in a right triangle are the trigonometric ratios, metric relationships, or the Pythagorean Theorem.

For solving this question, you need to apply the Pythagorean Theorem that says: (hypotenuse)²= (leg1)²+(leg2)².  

The question gives:

Hypotenuse= [tex]\sqrt{58}[/tex]Leg1= 2Leg2= third side = unknow

Applying the Pythagorean Theorem, you have:

([tex]\sqrt{58}[/tex])² = 2²+ x²

58=4+x²

x²=58-4

x²=54

x=[tex]\sqrt{54}[/tex]

x=[tex]\sqrt{2*3^3}[/tex]

x=[tex]\sqrt{2*3^2*3}[/tex]

x=3[tex]\sqrt{2*3}[/tex]

x=3[tex]\sqrt{6}[/tex]

Learn more about the Pythagorean theorem here:

brainly.com/question/11528638

#SPJ6


Which of the following is a ray shown in the drawing?

Answers

Answer:

So to get the answer we need to find both of the rays. So first we need to find the end points for the horizontal one. That would be D and E for the horizontal. Those are points, do the same for the diagonal one. AC would be it. AC and DE would be the answer

Rectangle ABCD is graphed in the coordinate plane. The following are the vertices of the rectangle: A(2, 1)B(5, 1),C(5, 6), and D(2, 6). Given these coordinates, what is the length of side AB of this rectangle?

Answers

Answer:

The legnth of side AB would be 3 units

Step-by-step explanation:

First, you would determine that both point A and point B would have the same y-coordinate of 1.   Then you would determine the difference between the x values of points A and B.  Since 5 (the x-value for B) minus 2 (the x-value for A) is 3, the legnth of side AB would be 3 units.

Step-by-step explanation:

I recommend using Desmos to quickly graph things (it's much faster than doing it yourself, I use it often. You can graph points and everything).

The picture ends up looking like the attachment I have below.

This is now a simple subtraction.

A is at 2 on the x-axis and B is at 5.

5-2=3

Answer:

3 units

which number produces an irrational number when multiplied bby 1/2

Answers

multiply by 0.4 will yield it

which function below is the inverse of f(x)= 7x-1/2

Answers

Answer: [tex]f^{-1}(x)=\frac{x}{7}+\frac{1}{14}[/tex]

Step-by-step explanation:

If we have y=7x-1/2, the inverse is where we solve for x instead of y.

We can isolate x to get 7x=y+1/2, then divide by 7 to get x=y/7+1/14.

Therefore, [tex]f^{-1}(x)=\frac{x}{7}+\frac{1}{14}[/tex].

Hope that helped,

-sirswagger21

Please answer correctly !!!!!! Will mark brainliest answer !!!!!!!!!

Answers

Answer:

(x+2)²+1

Step-by-step explanation:

because the graph we know that gx is (x+2)²+1

if a man walks for 6 miles at a steady speed of 3 mph how long will it take him

Answers

Answer:

It will take 2 hours

Step-by-step explanation:

6/3 = 2

Answer:

2 hours

Step-by-step explanation:

3 miles + 3 miles = 6 miles

1 hour + 1 hour = 2 hours

Find the slope of the line that passes through the points (-1, -2) and (-9, -2)

Answers

Answer:

0

Step-by-step explanation:

Ok use the equation: (Y2 - Y1) / (X2 - X1)

((-2) - (-2)) / ((-9)-(-1))

0/ -8

we know that 0 divided by any number is 0

so slope = 0

The formula for the area of a triangle is , where b is the length of the base and h is the height.

Find the height of a triangle that has an area of 30 square units and a base measuring 12 units.

3 units
5 units
8 units
9 units

Answers

Answer:

5 units

Step-by-step explanation:

The area of a triangle is given by

A = 1/2 bh

30 = 1/2 (12)h

Multiply

30 = 6h

Divide each side by 6

30/6 = 6h/6

5 = h

Answer:

5 units

Step-by-step explanation:

Next time please supply the formula, which was apparently given in this question:

A = (1/2)(base)(height)

Here, A = 30 units^2 = (1/2)(12 units)(height), or

                30 units^2 = (6 units)(height)

Solving for (height), we get

                 30 units^2

(height) = ------------------ = 5 units

                   6 units

The height is 5 units

You and a friend are trying to find a flag hidden in the woods. Your friend is standing
75 feet away from you. When facing each other, the angle from you to the flag is 720 and the angle from your friend to the flag is 53°. Is there enough information to locate
the flag?

Answers

Answer: Yes there is

Step-by-step explanation:

look bro your trying to get a total of 180 degrees

you already got 72 and 53 degrees

so add the two numbers and then subtract it from 180 degrees

thats 180 degrees minus 125 degrees

your missing point is 55 degrees

Find the sum of ( 1- 1/n) + (1 - 2/n) + ( 1 - 3/n)...upto n terms

Answers

Answer:

(n-1) / 2

Step-by-step explanation:

We have that the sum has the form of:

Sn = n / 2 [2 * a + (n-1) * d]

we compute the terms of a and d

a = 1 - 1 / n

a = (n - 1) / n

, that is, the first term, in the case d is the subtraction between the second and the first term, thus:

d = 1 - 2 / n - (1 - 1 / n)

d = 1 - 2 / n - 1 + 1 / n

d = - 1 / n

now if replacing these values:

Sn = n / 2 * [2 * (n - 1) / n + (n-1) * (- 1 / n)

Sn = n / 2 * [2 * (n-1) - (n-1)] / n

Sn = 1/2 * (n-1)

Therefore, the value of that sum is (n-1) / 2

I need help I keep getting it wrong

Answers

The answer is 360 cubic yards

Find the area of the triangle and multiply by the length of the prism.

Area = 1/2 x 8x3 = 12 square yds.

Volume = 12 x 6 = 72 cubic yards.

Would someone help me with this?

Answers

Answer:

A,E

Step-by-step explanation:

A    The minimum number of pages read was 24.  The smallest number is the dot on the left side which is at 24

E    The mean is the middle line in the box, this is at 48

When Jonathan bought 12 peaches and pears, at $1.50 per peach and
at $1.60 per pear, the total price was $18.50.
How many peaches and pears did he buy, respectively?
Fill in the blanks provided and solve for the answer.​

Answers

Answer 5 pears and 7 peaches

Explanation: you will need to make two equations to represent the problem
X being for peaches and y for pears
x+y= 12
1.5x + 1.6y= 18.5

We are going to use the elimination method and so we need to cancel either x or y in this case x. So we multiple the top equation by -1.5
-1.5x - 1.5y = -18
1.5x + 1.6y = 18.5

Then we can cancel the x since they are opposite and we can add the rest
0.1y =0.5
Y= 5
Then we can substitute the y into one of the equations
x + 5= 12
x= 7

1. Evan drove 308 km in the same time that Meghan drove 329 km. If Meghan drove
on average 6 km/h faster than Evan, calculate her average speed and the time taken
for the journey.

Answers

Answer:

Her average speed is 94 km/h

Time taken is 3.5 hours

Step-by-step explanation:

Let Evan’s average speed be x km/h.

now since Meghan drove faster, according to the question, we can say her average speed would be x + 6 km/h

Mathematically, time = distance/speed

so; since time is the same; we have

308/x = 329/(x + 6)

cross multiply

329(x) = 308(x + 6)

329x = 308x + 1848

329x-308x = 1848

21x = 1848

x = 1848/21

x = 88 km/h

Meghan average speed = x + 6 = 88 + 6 = 94 km/h

Time taken would be 329/94 = 3.5 hours

Which number is an integer?

-3/4 1/5 2 42/3

Answers

The Answer:

2 is an integer.

Answer:

c

Step-by-step explanation:

edgeinuity

Can I get help with this?

Answers

Answer:

Around 13.7

Step-by-step explanation:

The cosine of an angle in a right triangle is equivalent to the length of the adjacent side divided by the length of the hypotenuse. In this case, this means:

[tex]\cos 70= \dfrac{x}{40} \\\\x=40\cdot \cos 70\approx 13.7[/tex]

Hope this helps!

Mary is also a civil engineer, and she is building a triangular community garden. She knows two angles in the triangular garden, diagramed below. A triangle has angle measures 92 degrees, 27 degrees, and a degrees. The exterior angle to a degrees is b degrees. What are the measures of interior angle a and exterior angle b? a = ° b = °

Answers

Answer:

A= 61

B=119

Step by step:

a; interior angle

180-(27+92)

=180(119)

=61

b; exterior angle

180-61

=119

Answer: 61 and 119

Step-by-step explanation:

If AB = 3x + 5, BC = 2x + 8, and AC = 88, what is the value of x?

Answers

Answer:

x = 15

Step-by-step explanation:

AB + BC = AB

3x+5  + 2x+8 = 88

Combine like terms

5x +13 = 88

Subtract 13 from each side

5x+13-13 = 88-13

5x = 75

Divide each side by 5

5x/5 = 75/5

x = 15

Answer:

15

Step-by-step explanation:

AB + BC = AB

3x + 5 + 2x + 8 = 88

5x + 13 = 88

5x = 88 - 13

= 75/5

= 15

Hope this helps!

−12 − (−25) + 8
plzz helpp im not sure is it 21??

Answers

Answer:

21

Step-by-step explanation:

−12 − (−25) + 8

Subtracting a negative is like adding

-12 +25+8

First do -12 +25  25-12 = 13  Replace in the equation

13+8

21

Answer:

Yes, the answer is

[tex]21[/tex]

Step-by-step explanation:

we know that,

[tex]( - ) \times ( - ) = ( + )[/tex]

Now let's solve the problem,

[tex] - 12 - ( - 25) + 8 \\ - 12 + 25 + 8 \\ = 21[/tex]

hope this helps

brainliest appreciated

good luck! have a nice day!

9(2a – b)2 – 4(2a – b) – 13

Answers

18(2a-b)-4(2a-b)-13
=36a-18b-8a+4b-13
Rearrange
=36a-8a-18b+4b-13
=28a-14b-13

One number is 9 more than another number. The sum of the numbers is 25. What is one of the numbers?

Answers

Answer:

16? maybe

Step-by-step explanation:

i justed counted from 9 to 25,l

Answer:

8 or 17

Step-by-step explanation:

The system of equations for this is:

x = 9 + y

x + y = 25

Find the value of y by plugging the first equation into the second.

9 + y + y = 25

9 + 2y = 25

2y = 16

y = 8

One of the numbers is 8.

OR

Find the value of x by plugging the value of y into one o the equations.

x = 9 + 8

x = 17

or

x + 8 = 25

x = 17  

One of the numbers is 17.

Other Questions
This event occurs in lakes every year. Which season(s) does this eventoccur in ?1 point Based on the cartoon, explain the authors point of view about the Munich Agreement Consider the quadratic function f(x) = x2 5x + 6.What are the values of the coefficients and constant in the function?a=b = = The decline of the popularity of the Silk Road __________. Which graph shows exponential growth? Calculate the transfer of energy by a force of 15N when it moves the object by a distance of 5ma. In the direction of the forceb. In a direction at 60 to the direction of the forcec. At right angles to the forceNEED EXPLAINATION Are these functions??!!I need this for today if you do all of it ill fr cashapp you money for it wassupp? Which type of graphs allows the reader to view the raw data values?Select one or more:A Box PlotB Stem-and-leaf plotC Dot plotD Histogram Does Layeville's punishment fit his crime? Why or why not? Select all that apply. Which of the following are vertebrates? earthworms grasshopper lancelets octopus crab amphibians tunicates starfish Why is burning fossil fuels negative Which of the following are linear measurements?A) Length and widthB) Depth and heightC) Diameters, clearance, end play, and thicknessD) All of the above Im marking the brainliest :)) Find the length of both of the unknown sides in the triangle shown here.Give your answer correct to the nearest metre. [5 marks] What is System Racism? What does the narrator of"Chicago" see on the faces ofwomen and children?A joyB. hungerC. anger Please answer this correctly How might the purpose of the speech have influenced what Clinton said in it? what is juneteenth in your own word to not copy and paste from google do it in your ownword Which is f(6) for the quadratic function graphed?-2-0.51.54