A sample of 125 pieces of yarn had mean breaking strength 6.1 N and standard deviation 0.7 N. A new batch of yarn was made, using new raw materials from a different vendor. In a sample of 75 pieces of yarn from the new batch, the mean breaking strength was 5.8 N and the standard deviation was 1.0 N. Find a 90% confidence interval for the difference in mean breaking strength between the two types of yarn.

Answers

Answer 1

Answer:

The 90% confidence interval for the difference in mean breaking strength between the two types of yarn is (0.08N, 0.52N).

Step-by-step explanation:

Before building the confidence interval, we need to understand the central limit theorem and subtraction of normal variables.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

Subtraction of normal variables:

When we subtract two normal variables, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.

A sample of 125 pieces of yarn had mean breaking strength 6.1 N and standard deviation 0.7 N.

This means that [tex]\mu_1 = 6.1, s_1 = \frac{0.7}{\sqrt{125}} = 0.0626[/tex]

In a sample of 75 pieces of yarn from the new batch, the mean breaking strength was 5.8 N and the standard deviation was 1.0 N.

This means that [tex]\mu_2 = 5.8, s_2 = \frac{1}{\sqrt{75}} = 0.1155[/tex]

Distribution of the difference:

[tex]\mu = \mu_1 - \mu_2 = 6.1 - 5.8 = 0.3[/tex]

[tex]s = \sqrt{s_1^2+s_2^2} = \sqrt{0.0626^2+0.1155^2} = 0.1314[/tex]

Confidence interval:

We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:

[tex]\alpha = \frac{1 - 0.9}{2} = 0.05[/tex]

Now, we have to find z in the Ztable as such z has a pvalue of [tex]1 - \alpha[/tex].

That is z with a pvalue of [tex]1 - 0.05 = 0.95[/tex], so Z = 1.645.

Now, find the margin of error M as such

[tex]M = zs[/tex]

[tex]M = 1.645*0.1314 = 0.22[/tex]

The lower end of the interval is the sample mean subtracted by M. So it is 0.3 - 0.22 = 0.08N

The upper end of the interval is the sample mean added to M. So it is 0.3 + 0.22 = 0.52N

The 90% confidence interval for the difference in mean breaking strength between the two types of yarn is (0.08N, 0.52N).


Related Questions

For which value of k does Limit as x approaches kf(x) = 4?

0
2
6
8

Answers

Answer:

2

Step-by-step explanation:

on Edge

Answer: 2

Step-by-step explanation:

have a great day!

pls help Graph the rectangle after a 90° clockwise rotation about the origin.

Answers

Answer:

can you post the graph so I can answer to the best o my ability

Will give brainliest

Answers

Answer: Because the question uses the word “distinct” meaning obvious, and clear, I would select AB, AC, CB. (If it’s asking for all the possible line segments, I would select AB, AC, CB, BA, CA, BC).

he first date went well. You are still dating the same person and still looking for a great person to spend your life with. You are cautiously moving forward with the relationship and know that if they are a great match, their likelihood of being kind to animals is 0.9 whereas their likelihood of being kind to animals if they are not a great match is 0.7. You see that your prospective spouse is kind to animals. What is the probability that they are a great match now?

Answers

Answer:

0.125 = 12.5% probability that they are a great match now.

Step-by-step explanation:

To solve this question, we need the probability of a person being a great match, which i will use 0.1.

This question is solved using conditional probability.

Conditional Probability

We use the conditional probability formula to solve this question. It is

[tex]P(B|A) = \frac{P(A \cap B)}{P(A)}[/tex]

In which

P(B|A) is the probability of event B happening, given that A happened.

[tex]P(A \cap B)[/tex] is the probability of both A and B happening.

P(A) is the probability of A happening.

In this question:

Event A: Is kind to animals.

Event B: Is a great match.

Probability of being kind to animals:

0.9 of 0.1(Is a great match).

0.7 of 1 - 0.1 = 0.9(is not a great match). So

[tex]P(A) = 0.9*0.1 + 0.7*0.9 = 0.72[/tex]

Probability of being kind to animals and a great match:

0.9 of 0.1. So

[tex]P(A \cap B) = 0.9*0.1 = 0.09[/tex]

What is the probability that they are a great match now?

[tex]P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.09}{0.72} = 0.125[/tex]

0.125 = 12.5% probability that they are a great match now.

Male and female teachers were asked whether they preferred to use a whiteboard or a projector while teaching. The responses are summarized in the table. Projector Whiteboard Total Male 22 10 32 Female 28 15 Total 25 75 What is the approximate probability that a teacher prefers projectors and is female?

Answers

Answer: c is the answer

C: 0.560

Step-by-step explanation:

The probability that Joanne has eggs for breakfast and goes to school by car is 0.4. The probability that she goes to school by car on any day is 0.5. What is the probability that Joanne has had eggs for breakfast if she went to school by car?

A) .1
B) .2
C) .4
D) .5
E) .8

Answers

Answer:

A

Step-by-step explanation:

According to a report in USA Today (February 1, 2012), more and more parents are helping their young adult children get homes. Suppose 8 persons in a random sample of 40 young adults who recently purchased a home in Kentucky got help from their parents. You have been asked to construct a 95% confidence interval for the population proportion of all young adults in Kentucky who got help from their parents. You have been asked to construct a 95% confidence interval for the population proportion of all young adults in Kentucky who got help from their parents. What is the margin of error for a 95% confidence interval for the population proportion?

a.1.645(0.0040)
b.1.645(0.0632)
c.1.96(0.0040)
d.1.96(0.0632)

Answers

Answer:

d.1.96(0.0632)

Step-by-step explanation:

The margin of error for a 95% confidence interval for the population proportion calculated as below:

Given that x = 8

n = Size of the sample = 40 (Large sample)

Sample population: P=x/n = 8/40 = 0.2; q = 1-p = 0.8

Standard error = [tex]\sqrt{pq/n}[/tex] = [tex]\sqrt{0.2(0.8)}/40[/tex] = 0.0682

95% of confidence Z∝ = 1.96

Margin of Error = Z∝ .[tex]\sqrt{pq/n}[/tex]

Margin of Error = 1.96(0.0682)

So, therefore, option d is correct.

Which expression is equivalent to 4/9 × 7

key:
1. 9÷4×7
2. 4×7÷9
3. 4÷7×9
4. 7×9÷4

Thank you :)​

Answers

2 is the correct answer

Solve: 18^(x^(2)+4x+4)=18^(9x+18)


x = -2

x = 7

x = –2 and x = 7

no solution

Answers

Is this the problem?

[tex]18x^{2+4+4} = 18^{9x+18}[/tex]

Answer

The Answer is C                    

x=-2 and x=7                      

     

               

                                           

Find the measure of minor arc QN.

Answers

QN = 142°

A semicircle will always be equal to 180°, and we have two measures for semicircle QO.

[tex]QO = 180\\MN = 90\\NO = 38\\\\QM = QO - MN - NO\\QM = 180 - 90 - 38\\QM = 52\\\\QN = QM + MN\\QN = 52 + 90\\QN = 142\\[/tex]

Mr. Jackson earns $1,500 each week and his wife earns $850 a week. Each week they need to set aside $200 for food, $75 for gas, $625 for the mortgage, and $350 for savings. How much money will they have left each week?

Answers

Answer:

$1,100

Step-by-step explanation:

Given that

Earnings of Mr Jackson is $1,500

Earnings of his wife is $850

They need to set aside the following amounts

For foods, it would be $200

For gas, it would be $75

For Mortgage it would be $625

ANd, for savings, it would be $350

We need to find out the amount of money that they have left each week

So, the amount would be

= $1,500 + $850 - $200 - $75 - $625 - $350

= $1,100

Answer:

Step-by-step explanation:

The Hudson family is saving for a

family vacation to Disney World.  

They determine that the trip will

cost $3,200.  Mr. and Mrs.

Hudson have already set aside

$1,500 for the trip.  If they leave

in 16 weeks, then how much

will they need to save

each week?

Tinisha is planning a birthday party. She can buy:
10 balloons, 8 cupcakes, and 8 hats for $50
5 balloons, 9 cupcakes, and 7 hats for $46, or
12 balloons, 7 cupcakes, and 9 hats for $51
Using b for the number of balloons, c for the number of cupcakes, and h for
the number of hats, write a system of equations to represent this situation.

Answers

Answer:

b+c+h=50

Step-by-step explanation:

Its the first one because you need to have the same amount of hats as cupcakes cause the hat really stands for people.

Please assist me with this two column proof. Part 1A

Answers

Answer:

Answer is in the step by step explanation

Step-by-step explanation:

Since we are given parallel lines, we know <BCA is congruent to <DAC because of alternate interior angles

Then AC is congruent to AC, that's reflexive prop

Now we have SAS, so Tri. ABC cong to tri. CDA,

Then you're done

Answer:

Step-by-step explanation:

BC = AD                           Given

<BCA = <CAD                  Alternate interior angles of parallel lines cut by a transversal.

AC = AC                           That's the reflexive property. A line is equal to itself

Triangle BCA = Triangle CAD    SAS

Notice that the angle is included inside the two lines that define it (the angle). That's a very important consideration when using SAS. SAA doesn't always work. You can draw exceptions. SAS has no exceptions. It always works.

Rhianna has a spinner, which is divided into four equal parts. The parts are numbered 1, 2, 3, and 4. If Rhianna spins the spinner and tosses a coin, which table shows all the possible outcomes? 4 1 H1 H H 2 H2 H2 3. H3 H3 H4 4. O T T 1 11 T1 2 T2 T2 3 T3 T3 T4 1 4 H T 2 T2 T2 3 H3 H3 H1 4 0 T 1 T1 H1 2 T2 H2 3 T3 H3 H4​

Answers

Answer:

The bottom table.

Step-by-step explanation:

It's the only one that shows options for heads and tails for every number.

Answer:

D the last one

saniyah collected a total of 9 seashells she gave 1/3 to her sis how many seashells did Saniyah have left?

Answers

Answer: The answer is 3.

Step-by-step explanation: You would multiply 9x1/3 which would give you 3. If you want to understand even better here's how to do so: Put 3(the answer that you got from multiplying 9x1/3) into the fraction 1/3 as 1. In other words,  it would look something like this 3/3. Then, just multiply the two numbers 3x3 and that equals 9, the number you started with.

Hope that this helped!!:)

Considering the provided information in the given question, we have :

Total seashells Saniyah have = 9Number of seashells Saniyah gave to her sister = [tex]\sf \dfrac{1}{3} [/tex] of total.

We need to find how many seashells did Saniyah have left.

⇒ Number of seashells Saniyah have left = Total seashells – Number of seashells she gave to her sister

⇒ [tex] \sf {Left \: seashells = 9 - \Bigg \lgroup \dfrac{1}{3} \times 9 \Bigg \rgroup } [/tex]

⇒ [tex] \sf {Left \: seashells = 9 - \Bigg \lgroup 1 \times 3 \Bigg \rgroup } [/tex]

⇒ Left seashells = 9 – 3

⇒ Left seashells = 6

Therefore, Saniyah have left [tex] \bf {6 \: seashells } [/tex].

Which equation best represents the relationship
between x and y in the graph?
FOR BRAINLSIT!!

Answers

Answer:

I've never had to deal with this before but I would say C

Answer:

The best option is C ( y=(1/4) x +3)

betty closes the nozzle and fills it completely with a liquid. She then opens the nozzle. If the liquid drips at the rate of 14 cubic inches per minute, how long will it take for all the liquid in the nozzle to pass through(Use Pi = 3.14​

Answers

Answer:

4.71 minutes

Step-by-step explanation:

Incomplete question [See comment for complete question]

Given

Shape: Cone

[tex]r = 3[/tex] -- radius

[tex]h = 7[/tex] --- height

[tex]Rate = 14in^3/min[/tex]

Required

Time to pass out all liquid

First, calculate the volume of the cone.

This is calculated as:

[tex]V = \frac{1}{3} \pi r^2h[/tex]

This gives:

[tex]V = \frac{1}{3} * 3.14 * 3^2 * 7[/tex]

[tex]V = \frac{1}{3} * 197.82[/tex]

[tex]V = 65.94in^3[/tex]

To calculate the time, we make use of the following rate formula.

[tex]Rate = \frac{Volume}{Time}[/tex]

Make Time the subject

[tex]Time= \frac{Volume}{Rate }[/tex]

This gives:

[tex]Time= \frac{65.94in^3}{14in^3/min}[/tex]

[tex]Time= \frac{65.94in^3}{14in^3}min[/tex]

Cancel out the units

[tex]Time= \frac{65.94}{14} min[/tex]

[tex]Time= 4.71 min\\[/tex]

Answer:

The time it will take for all the liquid to pass through is 4.71 minutes.

-Don't worry it's been already verified by myself .

Joe ran 3 miles yesterday and wants to run at least 15 miles this week. Write an inequality that can be used to determine the additional number of days Joe must run this week if each run is 3 miles. Then solve the inequality.

Answers

9514 1404 393

Answer:

  3 +3d ≥ 15

  d ≥ 4

Step-by-step explanation:

Since Joe runs 3 miles for each day he runs, the number of miles he runs in d days is 3d. That, added to the distance he has already run, will total the amount for the week. He wants that to be at least (greater than or equal to) 15 miles:

  3 + 3d ≥ 15

__

We can divide by 3 to get ...

  1 + d ≥ 5

  d ≥ 4 . . . . . . . subtract 1

Joe must run at least 4 additional days this week to run at least 15 miles.

Scenario: The Cannon Instructions: View the video found on page 1 of this Journal activity. Using the information provided in the video, answer the questions below. Show your work for all calculations. The Cannon: Ernest's friend Nik is about to be shot out of a cannon. The path he will travel follows a parabolic arch that can be described by this polynomial. f(x) = –0.05(x2 – 26x – 120) He is supposed to land on a safety net 30 feet away. Does the function give you enough information to tell you where he will land? If so, how far from the cannon will he land?

Answers

Answer:

Part A

Yes

Part B

He will land at a point 30 meters from Cannon

Step-by-step explanation:

Part A

The given function that represent the path of the Cannon, which is the path of a parabolic arc, is presented as follows;

f(x) = -0.05·(x² - 26·x - 120)

We note that the height, 'h', of the path of a parabola at a horizontal distance, 'x' from the origin is equal to f(x)

Therefore, given that at the ground level, at the start and end of the flight, the f(x) = 0, we can write;

-0.05·(x² - 26·x - 120) = 0

∴ x² - 26·x - 120 = 0

x = (26 ± √((-26)² - 4 × 1 × (-120)))/(2 × 1)

Which gives;

x = 30 or x = -4

Therefore, he lands at a point 30 meters from the starting point

Therefore, the function gives enough information to tell where he will land

Part B

He lands at the point, x = 30 from the point the cannon was fired.

A sound wave with amplitude xo is measured by an observer to have an intensity of I0 when the observer is standing 4.0 meters from the source. Which best describes the amplitude of a sound wave and distance from the source where it will be measured with an intensity of 16Io?

Answers

Answer:

C) Increase the amplitude to 2xo and stand 2 meters from the source.

Step-by-step explanation:

Correct on Edge

A. 93
B. 57
C. 132
D. 123

Answers

Answer:

B

Step-by-step explanation:

The interior angles of a triangle always add up to 180 degrees.

We have two angles already and they add up to 60+63=123 degrees

180-123=57

so the remaining angle is 57 degrees

9514 1404 393

Answer:

  D.  123°

Step-by-step explanation:

The external angle is equal to the sum of the remote internal angles.

  m∠1 = 60° +63°

  m∠1 = 123°

20 POINTS!!!!!!!The monthly salary of an employee with 33 hours of training can be written as

Answers

Answer:

D-Salary(33) or S(33)

D is correct hope this helps

2 x - 3 / 5 = - 1 / 10

Answers

Answer:

1/4

Step-by-step explanation:

2x=-1/10 + 3/5

2x=1/2

x=1/4

A cylinder has a volume of 308 cubic inches and a height of 8 inches.What is the radius of the cylinder?Usr 3.14 for pie round to the nearest tenth of a unit

Answers

Answer: 3.5 inches

Step-by-step explanation:

Johnson Electronics makes calculators. Consumer satisfaction is one of the top
priorities of the company’s management. The company guarantees the refund of
money or a replacement for any calculator that malfunctions within two years from
the date of purchase. It is known from past data that despite all efforts, 12% of the
calculators manufactured by this company malfunction within a 2-year period. The
company recently mailed 550 such calculators to its customers.
a. Find the probability that exactly 32 of the 550 calculators will be returned for
refund or replacement within a 2-year period.
b. What is the probability that 30 or more of the 550 calculators will be returned for
refund or replacement within a 2-year period?
a. What is the probability that 15 to 35 of the 550 calculators will be returned for
refund or replacement within a 2-year period?

Answers

Answer:

later ill answer this .. read and understand

At the candy store, Sophie filled a bag with 2 2/3 kilograms of candy. 1/4 of the weight of the candy was from chocolate covered pretzels. How much did the chocolate covered pretzels in Sophie's bag weigh? ​

Answers

Answer:

The chocolate covered pretzels in Sophie's bag weighed [tex]\frac{2}{3} = 0.6667[/tex] kilograms.

Step-by-step explanation:

Sophie filled a bag with 2 2/3 kilograms of candy.

This means that the total weight is of:

[tex]2\frac{2}{3} = 2 + \frac{2}{3} = \frac{6}{3} + \frac{2}{3} = \frac{8}{3}[/tex]

The total weight is of 8/3 kilograms.

1/4 of the weight of the candy was from chocolate covered pretzels. How much did the chocolate covered pretzels in Sophie's bag weigh?

1/4 of 8/3. So

[tex]\frac{1}{4} \times \frac{8}{3} = \frac{1*8}{4*3} = \frac{2}{3} = 0.6667[/tex]

The chocolate covered pretzels in Sophie's bag weighed [tex]\frac{2}{3} = 0.6667[/tex] kilograms.

Victor drew trapezoid PQRS on a
coordinate plane. The coordinates of each
vertex are:
P(8,4) Q(10, 4) R(13, -1) S(8, -1)
tion
What is the length, in units, of side PS?
A. 2
B. 3
C. 4
D. 5

Answers

Answer:

Step-by-step explanation:

b

Answer:

b hope it helps make brainlliest ty

Step-by-step explanation:

can you make me brainlliest

Check the pic
please explain

Answers

Answer:

Option C

Step-by-step explanation:

From the picture attached,

In ΔABC,

m∠BAC + y° = 180° [Linear pair of angles are supplementary]

m∠BAC = 180° - y°

m∠ABC = x° [Vertically opposite angles]

m∠ACB = z° [Vertically opposite angles]

By triangle sum theorem,

m∠BAC + m∠ABC + m∠ACB = 180°

(180 - y)° + x° + z° = 180°

x - y + z = 180 - 180

x - y + z = 0

Option C will be the answer.

Choose the equation where b=6 is a solution. 11- b = 6 b + 4 = 9 8b = 48 63 b = 9

Answers

Answer:

8b = 48

Step-by-step explanation:

this is because you would substitute the b for the 6 and then multiply straight across giving you a total of 48.

Answer:

8b = 48

Step-by-step explanation:

8 x 6 = 48

20 POINTS HELP!!
What value of x and y make the polygon below a parallelogram

Answers

Answer:

Step-by-step explanation:

3x = 12

x=4

x+y =5y

4+y = 5y

4 = 4y

1=y

Answer:

x-5 = y

72 -5 = 67

y=67

x = 72

Step-by-step explanation:

In a parallelogram, the diagonals bisect each other.

That being the case,

6x = 72

x = 12 In a parallelogram, the diagonals bisect each other.

That being the case,

6x = 72

x = 12 and the diagonals measure

144 and 134

i hope this helps!! ^_^

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