Two companies manufacture a rubber material intended for use in an automotive application. The part will be subjected to abrasive wear in the field application, so we decide to compare the material produced by each company in a test. Twenty-five samples of material from each company are tested in an abrasion test, and the amount of wear after 1000 cycles is observed. For company 1, the sample mean and standard deviation of wear are

xÌ… = 20 milligrams / 1000cycless
s1= 2 milligrams/1000cycles and for company 2, you obtain

xÌ… 2 = 15 milligrams /1000cycles

and
s2= 8 milligrams / 1000cycles

Required:
a. Do the data support the claim that the two companies produce material with different mean wear? Use α = 0.05, and assume that each population is normally distributed but that their variances are not equal. What is the P-value for this test?
b. Do the data support a claim that the material from company 1 has higher mean wear than the material from company 2? Use the same assumptions as in part (a).
c. Construct confidence intervals that will address the questions in parts (a) and (b) above.

Answer:

A.) f(1) = 9, f(n + 1) = f(n) − 4; for n ≥ 1

Step-by-step explanation:

The first four terms of a sequence are shown below.

Let

f(1) = 9

f(2) = 5

f(3) = 1

f(4) = -3

Therefore we know that

f(2) - f(1) = 5 - 9

f(2) - f(1) = - 4

f(2) = f(1) - 4

f(3) - f(2) = 1 - 5

f(3) - f(2) = - 4

f(3) = f(2) - 4

f(4) - f(3) = -3 - 1

f(4) - f(3) = - 4

f(4) = f(3) - 4

Hence the answer is A.) f(1) = 9, f(n + 1) = f(n) − 4; for n ≥ 1

Answer:

Rewrite the expression using the negative exponent rule

rule b^-1 = 1/bn

1/2+x

Step-by-step explanation:

this is the correct answer you want.

1 foot = 12 inches.

Divide total inches by 12:

51 / 12 = 4.25 feet.

The whole number is the number of feet. Now multiply the decimal portion by 12 to get inches:

0.25 x 12 = 3 inches

51 inches = 4 feet 3 inches

The student is 4 feet 3 inches tall

If she is 51 inches, and you want to find the height in feet and inches, just add 12 each times from zero, and since 12 inches is equal to one foot, we can determine the following: 12 can go into 51 about 4 times, which is roughly 48 inches. Then, just subtract 48 from 51, and the answer to that is 3. And since we already know that 48 inches is 4 feet, then all you need to do is add the 3 inches that are left, and you get 4' 3'', or four feet and three inches. I hope this helps you, have a great day!

Answer:

Step-by-step explanation:

Answer:

haach f,f msfmavfb

Step-by-step explanation:

Answer:

5

Step-by-step explanation:

As given  

  1/sqrt2=x/5sqrt2

5sqrt2/sqrt2=x                Both sqrt will get cancelled

5=x

Answer:

C. 73 and 73

Step-by-step explanation:

An isosceles triangle has two angles that are the same, that narrows it down to C and D. The question states that there is only one 34° angle so it has to be C.

Answer:

C. 73° and 73°

Step-by-step explanation:

We know that the sum of interior angles in a triangle is equal to 180° and

Isosceles triangles has two angles with same measurement

it stated in the question that exactly one angle has measure of 34°

So the other two angles must be equal for the triangle to be isosceles

180 - 34 = 146 and this divided by 2

73° and 73° is the answer.

Answer:

50

Step-by-step explanation:

45 - 30 = 15

15 + 59 = 74

74 - 18 = 56

The mean change per day to Krista's account during the week is $ 14

What is Average?

The average value in a set of numbers is the middle value, calculated by dividing the total of all the values by the number of values.

Given data ,

The total sum of money in Krista's account = $45 - $30 + $59 - $18

                                                                             = $56

Total number of days = 4 days

Now ,

Mean change per day = Sum of money in Krista's account / Total number of days

Mean change per day  = 56 / 4

                                      = $ 14

Hence , The mean change per day to Krista's account during the week is $ 14

To learn more about average or mean click :

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Answer:

9x+1 is your answer

Step-by-step explanation:

2x+1+7x

2x+7x+1

9x+1

Answer:

9x+1

Step-by-step explanation:

2x+1+7x= 9x+1

can i have brainliest please

Answer:

320 cubic inches

Step-by-step explanation:

if I remember correctly you have to multiply the given numbers and then divide by that answer by 3 which gives you 320

Answer:

Volume of a rectangular pyramid  = (length x width x height) /3 cubic units.  

where W = 8 in,     h = 12 in,      L =  10 in.

Step-by-step explanation:

Volume = ( 10 x 8 x 12 ) /3 = 320 cubic inches.

I hope it help. Have a nice day.

five-digitsinceStep-by-step explanation:

Ummm.....I have never done this before but I THINK what your supposed to do is find the lcm of all the pairs you can get from those 3 numbers.

so lcm(16,56)=112

lcm(56,120)=840

lcm(16,120)=240

Now take any number from this and take the lcm of that

lcm(112,840)=1680

that is the number if you take the lcm of any of them so it is the lcm of them all but it is not a  number. so  16,56, and 120 are divisible by 2 I just multiplied 1680 by 2 until I got the highest possible 5 digit number which was 53760

Hope that helps :)

9514 1404 393

Answer:

  99120

Step-by-step explanation:

The LCM of 16, 56, 120 can be found from their factors:

  16 = 2^4

  56 = 2^3 · 7

  120 = 2^3 · 3 · 5

So, the least common multiple is 2^4×3×5×7 = 1680.

10^5/1680 = 59 r 880

The largest 5-digit number divisible by 16, 56, and 120 is 59×1680 = 99120.

D-(x-4)(4x+1) is your answer

Answer:

4x²-15x-4

doing middle term factorization

4x²-16x+x-4

4x(x-4)+1(x-4)

(x-4)(4x+1)

Answer:

y = 5x + 100

Step-by-step explanation:

Answer:

A

Step-by-step explanation:

This is a fraction equal to

6 miles ÷ 2 hours

We want a unit rate where

1 is in the denominator,

so we divide top and bottom by 2

6 miles ÷ 2 2 hours ÷ 2= 3 miles1 hour= 3 miles hour = 3 miles per hour

Answer:

the answer to this one is A.

Step-by-step explanation:

Answer:

We accept the null hypothesis, that is, that the population mean is not different from 0.7.

Step-by-step explanation:

A brochure claims that the average maximum height a certain type of plant is 0.7 m.

This means that the null hypothesis is:

[tex]H_{0}: \mu = 0.7[/tex]

A gardener suspects that this estimate is not accurate locally due to soil conditions.

Hypothesis test to determine whether the population mean is different from 0.7m, which means that the alternate hypothesis is:

[tex]H_{a}: \mu \neq 0.7[/tex]

The test statistic is:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.

0.7 is tested at the null hypothesis:

This means that [tex]\mu = 0.7[/tex]

A random sample of 43 plants is taken. The mean height of the plants in the sample is 0.65m.

This means, respectively, that [tex]n = 43, X = 0.65[/tex]

Assume that the population standard deviation is 0.2 m.

This means that [tex]\sigma = 0.2[/tex]

Value of the test statistic:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

[tex]z = \frac{0.65 - 0.7}{\frac{0.2}{\sqrt{43}}}[/tex]

[tex]z = -1.64[/tex]

Pvalue of the test:

Since we are testing that the mean is different of a value, and z is negative, the pvalue of the test is 2 multiplied by the pvalue of z = -1.64

z = -1.64 has a pvalue of 0.0505

2*0.0505 = 0.101

Using a 1% level of significance, perform a hypothesis test to determine whether the population mean is different from 0.7m.

0.101 > 0.01, which means that we accept the null hypothesis, that is, that the population mean is not different from 0.7.

Answer:

35

Step-by-step explanation:

Answer:

1:9

Step-by-step explanation:

9/9 = 1 and 81/9 = 9

Thus, 9:81 ratio simplified is 1:9

Answer:  $1.50 per ticket

Step-by-step explanation:

Divide 7.50 by 5 (You can do any of them. Like, 10.50/7 or 13.50/9 but you'll get the same answer.)

Once you divide them, you'll get 1.5.

$1.50 per ticket.

Not that bad

Answer:

A

Step-by-step explanation:

Answer:

209952=Area

56=Perimeter

Step-by-step explanation:

3*3*2*2*9*9*6*12=Area

3+3+2+2+9+9+6+12=Perimeter

Answer: Vertical angle proof

Step-by-step explanation: First off, this is really easy if you know how to do it. I think you should be able to figure it out. If you really are in collage. So Vertical angle proof, QPR is essentially (2x-30) but we need to find x. We know a triangle is 180 degrees and if it's a right angle then two angles add to 90.

So x+(2x+30)=90, 3x+30=90, 90-30=60, 3x=60, x=20. So there you have it. Now put x into the equation, 2(20)+30=70

70

Answer:

The answer is −6(10a−7)(a−10)

Step-by-step explanation:

1) Factor out the common term 6.

[tex] - 6( {10a}^{2} - 107a + 70)[/tex]

2) Split the second term in 10a² - 107a + 70 into two terms.

[tex] - 6( {10a}^{2} - 7a - 100a + 70)[/tex]

3) Factor out common terms in the first two terms, then in the last two terms.

[tex] - 6(a(10a - 7) - 10(10a - 7))[/tex]

4) Factor out the common term 10a - 7.

[tex] - 6( 10a - 7)(a - 10[/tex]

Therefor, the answer is -6 ( 10a - 7) (a - 10).

Answer:

16

Step-by-step explanation:

Number of Markers =

[tex]2 \div \frac{1}{8} \\ = 2 \times 8 \\ = 16[/tex]

Answer:

Inverse variation

Step-by-step explanation:

Required

What type of variation is described in the question

From the question, we understand that: the relationship is between time and temperature

The higher the time, the lower the temperature of the hamburger (to get freeze).

Hence, the relationship is an inverse variation.

So looking at the pattern you can tell that it is going by (-2)^(n-1)

if n=6 then we have (-2)^5 which is -32

The answers is D. -32

Answer:

A control group is used in an experiment as a point of comparison.

Step-by-step explanation:

By having a group that does not receive any sort of treatment, researchers are better able to isolate whether the experimental treatment did or did not affect the subjects who received it.

Answer: 24 Months

Step-by-step explanation: