An investigator compares the durability of two different compounds used in the manufacture of a certain automobile brake lining. A sample of 71 brakes using Compound 1 yields an average brake life of 41,628 miles. A sample of 31 brakes using Compound 2 yields an average brake life of 36,379 miles. Assume the standard deviation of brake life is known to be 4934 miles for brakes made with Compound 1 and 4180 miles for brakes made with Compound 2. Determine the 98% confidence interval for the true difference between average lifetimes for brakes using Compound 1 and brakes using Compound 2. Step 1 of 2 : Find the critical value that should be used in constructing the confidence interval.

Answers

Answer 1

Answer:

98%  Confidencce Interval is ( 3030.6, 7467.4 )

Step-by-step explanation:

Given that:

Sample size [tex]n_1 =[/tex] 71

Sample size [tex]n_2 =[/tex] 31

Sample mean [tex]\overline x_1 =[/tex] 41628

Sample mean [tex]x_2 =[/tex] 36,379

Population standard deviation [tex]\sigma_1[/tex] = 4934

Population standard deviation [tex]\sigma_2 =[/tex] 4180

At 98% confidence interval level, the level of significcance = 1 - 0.98 = 0.02

Critical value at [tex]z_{0.02/2} = 2.33[/tex]

The Margin of Error = [tex]z \times \sqrt{\dfrac{\sigma_1^2}{n_1}+\dfrac{\sigma^2_2}{n_2} }[/tex]

= [tex]2.33 \times \sqrt{\dfrac{4934^2}{71}+\dfrac{4180^2}{31} }[/tex]

= [tex]2.33 \times \sqrt{\dfrac{24344356}{71}+\dfrac{17472400}{31} }[/tex]

= [tex]2.33 \times \sqrt{906504.06 }[/tex]

= 2218.40

The Lower limit = [tex]( \overline x_1 - \overline x_2) - (Margin \ of \ error)[/tex]

= ( 41628 - 36379 ) - ( 2218.40)

= 5249 - 2218.40

= 3030.6

The upper limit = [tex]( \overline x_1 - \overline x_2) + (Margin \ of \ error)[/tex]

= ( 41628 - 36379 ) + ( 2218.40)

= 5249 + 2218.40

= 7467.4

∴  98%  Confidencce Interval is ( 3030.6, 7467.4 )


Related Questions

1. Simplify (–6x2 + x – 5) + (9x2 – 3x+6). ​

Answers

Answer:

= 7-2x. is the answer :p

Let U = {English, French, History, Math, Physics, Chemistry, Psychology, Drama}, A = {Chemistry, Psychology, Math, History}, B = {Drama, English, French, Math, History}, and C = {Physics, Psychology, French}. Find the following. n(B ∪ C)

Answers

Drama, English, French, Math, History, Physics, Psychology

8×4-5×(3⅕-2½)+(4-1)²​

Answers

Answer:

101/2

Step-by-step explanation:

Answer:

75/2

Step-by-step explanation:

Simplify the following:

8×4 - 5 (3 + 1/5 - (2 + 1/2)) + (4 - 1)^2

Put 2 + 1/2 over the common denominator 2. 2 + 1/2 = (2×2)/2 + 1/2:

8×4 - 5 (3 + 1/5 - (2×2)/2 + 1/2) + (4 - 1)^2

2×2 = 4:

8×4 - 5 (3 + 1/5 - (4/2 + 1/2)) + (4 - 1)^2

4/2 + 1/2 = (4 + 1)/2:

8×4 - 5 (3 + 1/5 - (4 + 1)/2) + (4 - 1)^2

4 + 1 = 5:

8×4 - 5 (3 + 1/5 - 5/2) + (4 - 1)^2

Put 3 + 1/5 - 5/2 over the common denominator 10. 3 + 1/5 - 5/2 = (10×3)/10 + 2/10 + (5 (-5))/10:

8×4 - 5(10×3)/10 + 2/10 + (5 (-5))/10 + (4 - 1)^2

10×3 = 30:

8×4 - 5 (30/10 + 2/10 + (5 (-5))/10) + (4 - 1)^2

5 (-5) = -25:

8×4 - 5 (30/10 + 2/10 + (-25)/10) + (4 - 1)^2

30/10 + 2/10 - 25/10 = (30 + 2 - 25)/10:

8×4 - 5(30 + 2 - 25)/10 + (4 - 1)^2

30 + 2 = 32:

8×4 - 5 (32 - 25)/10 + (4 - 1)^2

| 2 | 12

| 3 | 2

- | 2 | 5

| 0 | 7:

8×4 - 5×7/10 + (4 - 1)^2

-5×7/10 = (-5×7)/10:

8×4 + (-5×7)/10 + (4 - 1)^2

The gcd of -5 and 10 is 5, so (-5×7)/10 = ((5 (-1)) 7)/(5×2) = 5/5×(-7)/2 = (-7)/2:

8×4 + (-1×7)/2 + (4 - 1)^2

4 - 1 = 3:

8×4 - 7/2 + 3^2

8×4 = 32:

32 - 7/2 + 3^2

3^2 = 9:

32 - 7/2 + 9

Put 32 - 7/2 + 9 over the common denominator 2. 32 - 7/2 + 9 = (2×32)/2 - 7/2 + (2×9)/2:

(2×32)/2 - 7/2 + (2×9)/2

2×32 = 64:

64/2 - 7/2 + (2×9)/2

2×9 = 18:

64/2 - 7/2 + 18/2

64/2 - 7/2 + 18/2 = (64 - 7 + 18)/2:

(64 - 7 + 18)/2

| 1 |  

| 6 | 4

+ | 1 | 8

| 8 | 2:

(82 - 7)/2

| 7 | 12

| 8 | 2

- | | 7

| 7 | 5:

Answer: 75/2

If you used the input value 12 in the function y=2x,what would be the output value

Answers

Answer:

24

Step-by-step explanation:

If you put 12 in for x, you would get y=2*12 and 2 times 12 is 24. I hope this helps :)

Will mark Brainliest!!!!! Suppose A, R, and B are collinear on AB, and
AR: AB = 1/4 What are the coordinates of R?

Please give explanation

Answers

Answer:

[tex]R(x,y) = (\frac{7}{4},\frac{1}{4})[/tex]

Step-by-step explanation:

Given

[tex]A = (1,-1)[/tex]

[tex]B = (4,4)[/tex]

[tex]AR:AB = 1:4[/tex]

Required

Determine R

This question will be solved using line ratio formula

[tex]R(x,y) = (\frac{mx_2 + nx_1}{m+n},\frac{my_2+ny_1}{m + n})[/tex]

Where

[tex]A = (1,-1)[/tex]

[tex]B = (4,4)[/tex]

[tex]m:n = AR : RB[/tex]

Since R is on A and B;

[tex]AB = AR + RB[/tex]

[tex]4 = 1 + RB[/tex]

[tex]RB = 3[/tex]

Hence;

[tex]m:n = 1 : 3[/tex]

[tex]A = (1,-1)[/tex]

[tex]B = (4,4)[/tex]

[tex]R(x,y) = (\frac{mx_2 + nx_1}{m+n},\frac{my_2+ny_1}{m + n})[/tex] becomes

[tex]R(x,y) = (\frac{1 * 4 + 3 * 1}{1+3},\frac{1 * 4 + 3 * -1}{1 + 3})[/tex]

[tex]R(x,y) = (\frac{4 + 3}{4},\frac{4 - 3}{4})[/tex]

[tex]R(x,y) = (\frac{7}{4},\frac{1}{4})[/tex]

I WILL MARK BRAINLIEST!!!

What is 178.80 as a fraction?

Answers

Answer: 178 4/5 or as an improper fraction 894/5

Hope this helps!

Please mark Brainliest!

Answer:

178.80 = 178 + 0.8 = 178 + 8/10
178 8/10 = 178 4/5 or 895/5

Which description is correct for the polynomial 4x2+3x−2?




quartic trinomial

cubic binomial

quadratic trinomial

cubic trinomial

Answers

Answer:

Step-by-step explanation:

quadratic trinomial, because the highest degree of x is 2 and the expression has 3 terms.

A box contains 8 white balls, 7 black balls, & 2 red balls.
a) how many red balls must be added to the box so that the probability of drawing a red ball is 8/9
b)how many black balls must be added to the original box so that the probability of drawing a white ball is 1/9?

Answers

Answer:

a) 118

b) 55

Step-by-step explanation:

a) Originally, there are 2 red balls and a total of 17 balls.

8/9 = (2 + x) / (17 + x)

8 (17 + x) = 9 (2 + x)

136 + 8x = 18 + 9x

x = 118

b) Originally, there are 8 white balls and a total of 17 balls.

1/9 = 8 / (17 + x)

17 + x = 72

x = 55

After a 90% reduction, you purchase a new soft drink machine on sale for $64. What was the original price of the soft drink machine?

Answers

Answer:

$640

Step-by-step explanation:

Let [tex]x[/tex] equal the original price of the machine.

We know that $64 is 10% of [tex]x[/tex] because $64 is left of [tex]x[/tex] after the 90% reduction.

Set up an equation:

[tex].10x=64[/tex]

Divide by the coefficient of [tex]x[/tex], which in this case is [tex].10[/tex]

[tex]x=640[/tex]

what is the value of x​

Answers

Answer:

X=70

Step-by-step explanation:

Interior angles of parallel line sum up to be 180° so:

45+(2x-5)=180

45+2x=185

2x=140

x=70

put these numbers -23, 2, 0.7, 5, 16,0, 3.89, -4 in sections of rational, irrational, whole numbers, and integers

Answers

Vocabulary Check:

Integers are numbers that are neither fractions nor decimals.

Rational numbers are numbers that can be written as a fraction, unlike irrational numbers. Whole numbers are counting numbers, including 0.

Integers = -23, 2, 3, 16, 0, -4

Whole Numbers = 0, 2, 3, 16

Rational = -23, 2, 0.7, 5, 16, 0, 3.89, -4

Irrational: None

HELP PLZ AND.... HIIIII!

Answers

Answer:

0.002 meters per second

Answer: 0.0002 meters per second

vertices of parallelogram ABCD are A(2, 0), B(4, 3), C(3, 1). How many possibilities are there for the position of the fourth vertex?

Answers

Answer:

1 possibility is there for the the position of the fourth vertex.

how do i math? plssssssssssssssssss answer

Answers

Answer:

you just math you know pretty easy when you know what to do

Step-by-step explanation:

just practice

Ava is 23cm taller than Olivia, and Olivia is half the height of Lucas. If Lucas is is 1.78m tall, how tall is Ava and Olivia?

Answers

you must convert 1.89 meters into centimeters, which is 189 then divide it into 2, which is 94.5, then add 23, which is 117.5 so your answer is

117.5 !! good luck :)

Answer:

Ava = 1.12 m tall

Olivia =  0.89 m tall

Step-by-step explanation:

given;

Ava is 23cm taller then Olivia,

Olivia is half the height of Lucas.

If Lucas is 1.78m tall

find:

how tall are Ava and Olivia

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

Ava = Olivia + 0.23

Olivia = Lucas / 2

Lucas = 1.78

plugin values into the equation above

Olivia = 1.78 / 2

Olivia =  0.89 m tall

Ava = 0.89 + 0.23

Ava = 1.12 m tall

(c) Given that the system has at least one type of defect, what is the probability that it has exactly one type of defect

Answers

Answer:

The probability is 0.357

Step-by-step explanation:

Given that,

The system has at least one type of defect,

Suppose, A certain system can experience three different types of defects.

Let [tex]A_{i}[/tex] (i = 1,2,3) denote the event that the system has a defect of type i.

Suppose that the following probabilities are,

[tex]P(A_{1})=0.11[/tex]

[tex]P(A_{2})=0.08[/tex]

[tex]P(A_{3})=0.05[/tex]

[tex]P(A_{1}\cup A_{2})=0.13[/tex]

[tex]P(A_{1}\cup A_{3})=0.13[/tex]

[tex]P(A_{2}\cup A_{3})=0.11[/tex]

[tex]P(A_{1}\cap A_{2}\cap A_{3})=0.01[/tex]

[tex]P(A_{1}\cap A_{2})=0.06[/tex]

[tex]P(A_{1}\cap A_{3})=0.03[/tex]

[tex]P(A_{2}\cap A_{3})=0.02[/tex]

[tex]P(A_{1}\cup A_{2}\cup A_{3})=0.14[/tex]

We need to calculate the probability that it has exactly one type of defect

Using given data

[tex]P=\dfrac{P(A_{1}\cap A_{2}'\cap A_{3}')}{P(A_{1}\cup A_{2}\cup A_{3})}+\dfrac{P(A_{1}'\cap A_{2}\cap A_{3}')}{P(A_{1}\cup A_{2}\cup A_{3})}+\dfrac{P(A_{1}'\cap A_{2}'\cap A_{3})}{P(A_{1}\cup A_{2}\cup A_{3})}[/tex]

[tex]P=\dfrac{P(A_{1})-P(A_{1}\cap A_{2})-P(A_{1}\cap A_{3})+P(A_{1}\cap A_{2}\cap A_{3})}{P(A_{1}\cup A_{2}\cup A_{3})}[/tex] + [tex]\dfrac{P(A_{2})-P(A_{1}\cap A_{2})-P(A_{2}\cap A_{3})+P(A_{1}\cap A_{2}\cap A_{3})}{P(A_{1}\cup A_{2}\cup A_{3})}[/tex]+ [tex]\dfrac{P(A_{3})-P(A_{1}\cap A_{3})-P(A_{2}\cap A_{3})+P(A_{1}\cap A_{2}\cap A_{3})}{P(A_{1}\cup A_{2}\cup A_{3})}[/tex]

P = [tex]\dfrac{P(A_{1})+P(A_{2})+P(A_{3})-2P(A_{1}\cap A_{2})-2P(A_{1}\cap A_{3})-2P(A_{2}\cap A_{3})+3P(A_{1}\cap A_{2}\cap A_{3})}{P(A_{1}\cup A_{2}\cup A_{3})}[/tex]

Put the value into the formula

[tex]P=\dfrac{0.11+0.08+0.05-2(0.06)-2(0.03)-2(0.02)+3(0.01)}{0.14}[/tex]

[tex]P=0.357[/tex]

Hence, The probability is 0.357

Is this relation a function?

Answers

yes that is a function because every number has a pair that goes to each other once

Two jugs and 4 bottles hold 40 ounces. One jug and 3 bottles hold 25 ounces. How many ounces does 1 jug hold?

Answers

Answer:

5 ounces

Step-by-step explanation:

Let the capacity of jug be j, bottle be b

[tex]2j + 4b = 40 \\ j + 3b = 25 \\ j = 25 - 3b \\ \\ therefore \: 50 - 6b + 4b = 40 \\ 2b = 10 \\ b = 5[/tex]

Heidi Muir, a sporting goods wholesaler, purchased goods from a supplier for $3,400. The
supplier offers a 3% discount if the invoice is paid within 10 days; if not paid within 10 days, the
full amount must be paid within 30 days of the invoice date. Use the formula to find the annual
rate Heidi, in effect, is paying the supplier if she fails to pay the invoice at the end of the discount
period

Answers

Answer:

56.44%

Step-by-step explanation:

From the question, we have the following values

% Discount = 3%

Full allowed payment days = 30 days

Discount days = 10 days

1 year = 365 days

The formula for Effective Annual rate or Annual rate in effect =

Discount %/(1-Discount %) x (365 days/(Full allowed payment days - Discount days))

= 3%/(1 - 3%) × (365 days/30 days - 10 days)

= 0.03/(1 - 0.03) × (365/20)

= 0.03/0.97 × (365/20)

= 0.5644329897

Converting to percentage

0.5644329897 × 100

= 56.44329897%

Approximately = 56.44%

Therefore, the annual rate Heidi, in effect, is paying the supplier if she fails to pay the invoice at the end of the discount period is 56.44%

Evaluate –32 + (2 – 6)(10

Answers

Steps to solve:

-32 + (2 - 6)(10)

~Simplify

-32 + (-4)(10)

~Multiply

-32 - 40

~Subtract

-72

Best of Luck!

Answer:

The answer is -49

Step-by-step explanation:

The equation is: –32 + (2 – 6)(10).

Then u have to do PEMDAS

P=Parentheses

E=Exponents

M=Multiplication

D=Division

A=Addition

S=Subtraction

you follow the steps to get -49

Which choice correctly expresses the number below in scientific notation?

Answers

Answer:

I think 2nd option is correct

the answer is D because there is seven zeros

Which equation must be true for m(x) and n(x) to be inverse?

Answers

Answer:

  see below

Step-by-step explanation:

When the functions are inverses of each other, it will be true that ...

  m(n(x)) = n(m(x)) = x

The expanded form of this equation is shown below.

In a paint store you’re mixing paint for a larger order. Paint requires mixture of 75% base 25% color. How many gallons of base should you mix for 4 gallons of color ?

Answers

12 gallons of base are needed

The temperature in Miami, Florida is 22 degrees warmer than three times the temperature in Bangor, Maine. The temperature in Miami is 82 degrees. Write an equation to determine the temperature in Bangor.

Answers

Answer:

See Explanation

Step-by-step explanation:

Let the temperatures of Miami and Bangor be M and B degrees respectively.

According to the given information:

M = 3B + 22... (required equation)

Plug M = 82

82 = 3B + 22

82 - 22 = 3B

60 = 3B

B = 60/3

B = 20 degrees

Thus, the temperature in Bangor is 20 degrees.

The required temperature in Bangor is 52 degrees and the required equation is 82 = 3B + - 22.

Given that,
The temperature in Miami, Florida is 22 degrees warmer than three times the temperature in Bangor, Maine.
The temperature in Miami is 82 degrees.
An equation to determine the temperature in Bangor is to be determined.

What is arithmetic?

In mathematics, it deals with numbers of operations according to the statements. There are four major arithmetic operators, addition, subtraction, multiplication and division,

Here,
Let the temperature in Bangor be B
The temperature in Miami is 82 degrees.
The temperature in Miami, Florida is 22 degrees warmer than three times the temperature in Bangor. Implies,

82 = 3B + - 22
3B = 82 + 22
3B = 104
B = 52 degrees

Thus, the required temperature in Bangor is 52 degrees.

Learn more about arithmetic here:

brainly.com/question/14753192

#SPJ2

the square root of a number, less than nine (write into a verbal expression)

Answers

Answer: 9 - [tex]\sqrt{x}[/tex]

Step-by-step explanation:

Let say the number is x.

So the square root of x will  be [tex]\sqrt{x}[/tex]  and is less than 9  so we will subtract that from 9.

[tex]9-\sqrt{x}[/tex]

Before going to bed, Maria's
temperature was 103,2º. Her fever
broke in the night so that her
moming temperature was 3.7
degrees lower. What was Mana's
temperature the next morning?

Answers

Answer:

Her temperature was 99.5°

Step-by-step explanation:

103.2 - 3.7 = 99.5

If Ben invests $3000 at 4% interest per year, how much additional money must he invest at 5.5 % annual interest to ensure that the interest he receives each year is 4.5 % of the total amount invested?

Answers

Answer:

$1500

Step-by-step explanation:

Investment 1 = $3000Interest 1 = 4%Investment 2 = xInterest 2 = 5.5%Total interest = 4.5%

Total interest:

3000*0.04 + x*0.055 = (3000+ x)*0.045    ⇒ multiply by 100 both sides3000*4 + 5.5x = 3000*4.5 + 4.5x                ⇒ parenthesis5.5x - 4.5x = 3000(4.5-4)                             ⇒ collect like termsx = 3000*0.5                                                ⇒ simplifyx = 1500                                                        ⇒ answer

Additional money is $1500

Please explain how this digraph works.

Answers

Angles XQL and MQR are congruent because they are vertical angles. So

209 - 13 b = 146 - 4 b

Solve for b :

209 - 13 b = 146 - 4 b

209 - 146 = 13 b - 4 b

63 = 9 b

b = 63/9 = 7

Then the measure of angle XQL is

(209 - 13*7)º = 118º

An eastern airport has recorded a monthly average of five near misses of landings and takeoffs in the past 5 years. We assume that the distribution of this number is Poisson. a. Find the probability that during a given month there are no near misses on landings and takeoffs at the airport. b. Find the probability that during a given month there are five near misses. c. Find the probability that there are at least five near misses during a particular month.

Answers

Answer:

The answer to this question can be defined as follows:

In option a "0.0067".

In option b "0.1755".

In option c "0.5595".

Step-by-step explanation:

It is about the distribution of Poisson:

[tex]\lambda = 5 (rate)[/tex]

t = 1

The formula for calculating Mean:  

[tex]\to \mu = \lambda \times t[/tex]

[tex]\to P(X=x) = \frac{e^{-\mu} \mu^{x}}{x!}[/tex]

calculate the value of Mean:

[tex]\to \mu =5 \times 1\\\\ \to \mu= 5[/tex]

In point a:

When the value of x is equal to 0:

[tex]\to P(X = 0) = \frac{e^{-5} 5^{0}}{0!}[/tex]

                    [tex]= \frac{e^{-5} \times 1 }{0}\\\\ = 0.0067 \times 1 \\\\ = 0.0067[/tex]

In point b:

When the value of x is equal to 5:

[tex]\to P(X = 0) = \frac{e^{-5} 5^{5}}{5!}[/tex]

                    [tex]= \frac{e^{-5} \times 3125 }{120}\\\\ = \frac{0.0067 \times 3125}{120} \\\\ = \frac{21.0560}{120}\\\\ =0.1754 \\\\[/tex]

In point c:

When the value of x is equal to 5:

[tex]\to P(X \ge 5) = 1 - P(X < 5) \\\\ \to P(X \ge 5) = 1 - P(X = 0) - P(X = 1) - P(X = 2) - P(X = 3) - P(X = 4) \\\\ \to P(X \ge 5) = 0.5595[/tex]

Find the unit rate of 90 miles/2 hours, IN FEET PER SECOND! can you please do it step by step plz?

Answers

Answer:

45, 90/2 equals 45. everytime you need to find it you do miles/hours

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