An investigator compares the durability of two different compounds used in the manufacture of a certain automobile brake lining. A sample of 127 brakes using Compound 1 yields an average brake life of 42,814 miles. A sample of 163 brakes using Compound 2 yields an average brake life of 37,197 miles. Assume that the population standard deviation for Compound 1 is 1819 miles, while the population standard deviation for Compound 2 is 1401 miles. 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 3 is Point estimate so 42,814 - 37,197 = 5,617
Step 2 of 3 :
Calculate the margin of error of a confidence interval for the difference between the two population means. Round your answer to six decimal places.
Step 3 of 3:
Construct the 98% confidence interval. Round your answers to the nearest whole number. (lower and upper endpoint)

Answer:

177.3 feet

This is a classic find the vertex of a parabola question.

if this was a calculus class the solution would be to take the derivative and set it equal to zero... -32t+ 105 = 0

BUT i assume that you are not in a calculus class..

so we try plan "B" the  highest (or lowest) point of parabola is it's vertex

the vertex formula is [-b/2a,f(-b/2a)]

in your problem a = -16, b=105, c= 5

so the "X" (TIME) is located at -(105)/(2*-16) = 3.28

plug in 3.28 into -16(3.28)^2 + 105(3.28) + 5 = 177.27

and you will get

Step-by-step explanation:

Answer:

Add 81/4 to both sides.

Step-by-step explanation:

x^2 − 9x − 8 = 0

x^2 - 9x = 8

Take the coefficient of the x term: -9

Divide by 2: -9/2

Square it: 81/4

Add 81/4 to both sides.

Answer:

x=-6

Step-by-step explanation:

For the rational expression, 6x/(x+6) to be undefined, the denominator need to be 0, so x=-6 is the point at which the function is undefined.

The rational expression 6x / (x + 6) is undefined when x equals -6, and it is defined for all other real numbers.

To find the real numbers for which the rational expression 6x / (x + 6) is undefined, we need to identify the values of x that would make the denominator equal to zero. When the denominator is zero, the expression becomes undefined.

In this case, the denominator is (x + 6). Setting the denominator equal to zero, we have:

x + 6 = 0

Solving for x, we subtract 6 from both sides:

x = -6

Therefore, the rational expression 6x / (x + 6) is undefined when x = -6.

When x is equal to -6, the denominator becomes zero, which causes division by zero. Division by zero is undefined in mathematics. Hence, for x = -6, the rational expression is not defined.

For any other real numbers other than x = -6, the expression is defined and can be simplified or evaluated.

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Answer:

I have no clue my bad bro.

The area of the square field is 67600 m² and the side is 260 m long.

A quadrilateral with all sides equal and all angles are right angles.

Given that, a person takes 40 paces to cover 20 m of a square field according to him the field has a side that is 520 paces long, we need to find the measure of the side and the area,

Since,

40 paces = 20 m

1 pace = 1/2 m

Therefore,

520 paces = 0.5 x 520 m

= 260 m

Therefore, the square field is 260 m long,

Area of the square field = side² = 260²

= 67600 m²

Hence, the area of the square field is 67600 m² and the side is 260 m long.

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Answer:

Amanda's box is in this case, the bigger one. Then subtract the Amanda's by Mary's. The Larger box is 70cm^3 larger then the smaller box.

Step-by-step explanation:

Amanda's box: 13.5*10*10= 1350cm^3

Mary's box: 20*8*8= 1280cm^3

1350-1280=70

The larger box is 70cm^3 larger then the smaller box.

If you have any questions regarding my answer tell me in the comments, i will come answer them. Have a good day.

Answer:

[tex]- \frac{\pi}{3}[/tex]

Step-by-step explanation:

Given

[tex]y = -3\cos(3x - \pi) + 5[/tex]

Required

The phase

We have:

[tex]y = -3\cos(3x - \pi) + 5[/tex]

Rewrite as:

[tex]y = -3\cos(3(x - \frac{\pi}{3})) + 5[/tex]

A cosine function is represented as:

[tex]y = A\cos(B(x + C)) + D[/tex]

Where:

[tex]C \to[/tex] Phase

By comparison:

[tex]C = - \frac{\pi}{3}[/tex]

Hence, the phase is: [tex]- \frac{\pi}{3}[/tex]

Answer:

Mathematical induction can be used to prove that an identity is valid for all integers n≥1. Here is a typical example of such an identity: 1+2+3+⋯+n=n(n+1)2. More generally, we can use mathematical induction to prove that a propositional function P(n) is true for all integers n≥1.

Step-by-step explanation:

I'd really appreciate a brainleast please:)

Answer:

the answer is 0.31/ 5.1/8.57.1% /207067

Step-by-step explanation:

ascending order from the smallest to the largest

30,20 and 10

30 + 20 + 1/3×30 = 60

50 + 10 = 60

60 = 60

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Answer:

the scale factor is 3/4

x = 16×3/4 = 12

Step-by-step explanation:

the only side length we have for both triangles is the short left side.

we see that we get ED from SR and need to transform 4 into 3. how do we do that ?

well,

4×f = 3

f = 3/4

that is the scaling factor, as all side lengths in EDF are created by multiplying the corresponding side in SRT by the same scaling factor (3/4).

therefore,

x = EF = ST×f = 16×3/4 = 4×3 = 12

Answer:

The scale factor is 4/3 and x is 12

Step-by-step explanation:

→ Divide RS by DE

4 ÷ 3 = 4/3

→ Divide the answer by 16

16 ÷ 4/3 = 12

Answer:

20% of students prefer to go to the aquarium

50% of teachers prefer to go to the aquarium

Step-by-step explanation:

1.

8 students prefer the aquarium out of 40 students.

Set up an equation:

Variable x = percentage of students

8/40 = x/100

Cross multiply:

8 × 100 = 40 × x

800 = 40x

20 = x

Divide:

20%

Check your work:

40 students × 20%

Convert percentage into decimal:

40 × 0.20

8

8 students prefered the aquarium so this is correct!

2.

5 teachers prefer the aquarium out of 10 teachers.

Set up an equation:

Variable x = percentage of teachers

5/10 = x/100

5 × 100 = 10 × x

500 = 10x

50 = x

50%

Check your work:

10 × 0.50

5

Correct!

Answer:

128/3

Step-by-step explanation:

The sequence follow the rule (1/6)*(4)^(n-1). The 5th term will be (1/6)*(4)^4=128/3

Answer:

128/3

Step-by-step explanation:

1/6, 2/3, 8/3, . . .

1/6, 4/6, 16/6

We are multiplying by 4 each time

1/6 *4 = 4/6

4/6 * 4 = 16/6

This is a geometric sequence with the common ratio of 4

an = a1 (r)^(n-1)

an = 1/6 (4) ^(n-1)

Let n = 5

a5 = 1/6 (4)^(5-1)

a5 = 1/6 (4)^4

a5 = 1/6 * 256

a5 =128/3

Problem 4a

The instructions are incomplete. You set up the recursive formula, but didn't ask any question about said formula.

I'll assume that your teacher wants you to list out a few terms. I'll list out the first five terms.

The notation a_1 = 4 is the same as writing [tex]a_1 = 4[/tex] where the '1' is a subscript. It tells us that the first term is 4.

The nth term a_n or [tex]a_n[/tex] is defined as such

[tex]a_n = 2*(1/3 + a_{n-1})\\\\[/tex]

Notice how if we replaced n with 2, then we get

[tex]a_n = 2*(1/3 + a_{n-1})\\\\a_2 = 2*(1/3 + a_{2-1})\\\\a_2 = 2*(1/3 + a_1)\\\\[/tex]

So the second term is directly tied to the first term, or it is dependent on it.

We'll replace a_1 with 4 to get the following

[tex]a_2 = 2*(1/3 + a_1)\\\\a_2 = 2*(1/3 + 4)\\\\a_2 = 2*(1/3 + 12/3)\\\\a_2 = 2*(13/3)\\\\a_2 = 26/3\\\\[/tex]

So the second term is 26/3.

As you can guess, the third term is going to be found in a similar fashion

[tex]a_n = 2*(1/3 + a_{n-1})\\\\a_3 = 2*(1/3 + a_{3-1})\\\\a_3 = 2*(1/3 + a_2)\\\\a_3 = 2*(1/3 + 26/3)\\\\a_3 = 2*(27/3)\\\\a_3 = 2*(9)\\\\a_3 = 18\\\\[/tex]

So 18 is the third term.

We'll repeat for n = 4 to get the fourth term.

[tex]a_n = 2*(1/3 + a_{n-1})\\\\a_4 = 2*(1/3 + a_{4-1})\\\\a_4 = 2*(1/3 + a_3)\\\\a_4 = 2*(1/3 + 18)\\\\a_4 = 2*(1/3 + 54/3)\\\\a_4 = 2*(55/3)\\\\a_4 = 110/3\\\\[/tex]

The fourth term is 110/3.

Lastly, we'll plug in n = 5

[tex]a_n = 2*(1/3 + a_{n-1})\\\\a_5 = 2*(1/3 + a_{5-1})\\\\a_5 = 2*(1/3 + a_4)\\\\a_5 = 2*(1/3 + 110/3)\\\\a_5 = 2*(111/3)\\\\a_5 = 2*(37)\\\\a_5 = 74\\\\[/tex]

The fifth term is 74.

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

Problem 4b

Again, the instructions are missing. I'll assume the same thing as problem 4a.

[tex]a_1 = 6[/tex] is the first term

Plug n = 2 into the first equation to get

[tex]a_n = \frac{n}{a_{n-1}}\\\\a_2 = \frac{2}{a_{2-1}}\\\\a_2 = \frac{2}{a_{1}}\\\\a_2 = \frac{2}{6}\\\\a_2 = \frac{1}{3}\\\\[/tex]

The second term is 1/3.

Repeat for n = 3

[tex]a_n = \frac{n}{a_{n-1}}\\\\a_3 = \frac{3}{a_{3-1}}\\\\a_3 = \frac{3}{a_{2}}\\\\a_3 = \frac{3}{1/3}\\\\a_3 = 3\div\frac{1}{3}\\\\a_3 = 3\times\frac{3}{1}\\\\a_3 = 9\\\\[/tex]

The third term is 9

Repeat for n = 4.

[tex]a_n = \frac{n}{a_{n-1}}\\\\a_4 = \frac{4}{a_{4-1}}\\\\a_4 = \frac{4}{a_{3}}\\\\a_4 = \frac{4}{9}\\\\[/tex]

The fourth term is 4/9

Repeat for n = 5

[tex]a_n = \frac{n}{a_{n-1}}\\\\a_5 = \frac{5}{a_{5-1}}\\\\a_5 = \frac{5}{a_{4}}\\\\a_5 = 5 \div a_{4}\\\\a_5 = 5 \div \frac{4}{9}\\\\a_5 = 5 \times \frac{9}{4}\\\\a_5 = \frac{5}{1} \times \frac{9}{4}\\\\a_5 = \frac{5*9}{1*4}\\\\a_5 = \frac{45}{4}\\\\[/tex]

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

Problem 4c

I'm not much help here for this problem. Not only are the instructions missing, but it's not clear how this sequence is set up. If I had to guess, it's somehow recursively defined. How exactly, I'm not sure. I would ask your teacher for any clarification.

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

Explanation:

Let

r = area devoted to residential use

This variable is some positive real number, and it represents the area in acres.

Your teacher says that " the area devoted to business use is 7,200 acres less than the area devoted to residential use"

This means the expression r-7200 represents the area for business use

Note the jump from 25% to 65% is 65/25 = 2.6, meaning that we multiply by 2.6 when going from the business area to the residential area.

So we'll multiply by 2.6 to go from r-7200 to r

We'll have this equation

2.6(r-7200) = r

because it's effectively saying

2.6*(business area) = residential area

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

Let's isolate r

2.6(r-7200) = r

2.6r-2.6*7200 = r

2.6r - 18720 = r

2.6r - r = 18720

1.6r = 18720

r = 18720/(1.6)

r = 11700

We'll use 11700 acres for the residential portion.

And also r-7200 = 11700-7200 = 4500 acres are set aside for the business district.

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

The largest region (residential) uses 11700 acres of land.

Note the jump from 10% to 65% involves a multiplier of 6.5 because 65/10 = 6.5

So if g is the amount of government land used, then,

6.5g = r

6.5g = 11700

g = 11700/(6.5)

g = 1800

1800 acres of land are for government use

This is why the answer is choice B.

The area, in acres, devoted to government use is 1800.

Option (B) is correct.

To find the area.

Percentage, a relative value indicating hundredth parts of any quantity.

Given that:

Let

r = area devoted to residential use

This variable is some positive real number, and it represents the area in acres.

This means the expression r-7200 represents the area for business use

Note the jump from 25% to 65% is 65/25 = 2.6, meaning that we multiply by 2.6 when going from the business area to the residential area.

To multiply by 2.6 to go from r-7200 to r

The equation is

2.6(r-7200) = r

because it's effectively saying

2.6*(business area) = residential area

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

Let's isolate r

2.6(r-7200) = r

2.6r-2.6*7200 = r

2.6r - 18720 = r

2.6r - r = 18720

1.6r = 18720

r = 18720/(1.6)

r = 11700

We'll use 11700 acres for the residential portion.

And also r-7200 = 11700-7200 = 4500 acres are set aside for the business district.

The largest region (residential) uses 11700 acres of land.

Note the jump from 10% to 65% involves a multiplier of 6.5 because 65/10 = 6.5

So if g is the amount of government land used, then,

6.5g = r

6.5g = 11700

g = 11700/(6.5)

g = 1800

So, the area, in acres, devoted to government use is 1800.

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Answer:

b = h*D +hg^3

Step-by-step explanation:

b/h = D +g^3

Multiply each side by h

h* b/h = h*D +hg^3

b = h*D +hg^3

The unit rate will be "23.5 miles/gallon". In the below segment, a further solution to the given question is provided.

Given values in the question are:

Total distance,

= 188 miles

Total gas used,

= 8

Now,

⇒ The rate of gas consumption will be:

= [tex]\frac{Total \ distance}{Total \ gas \ used}[/tex]

By putting the given values in the above formula, we get

= [tex]\frac{188}{8}[/tex]

= [tex]23.5 \ miles/gallon[/tex]

Thus the above is the appropriate solution.

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The solutions are where the two lines cross over each other.

(0,3) and (4,-5)

Answer:

y<=(-2x+4)

Step-by-step explanation:

The equation of line is y=-2x+4. For the region left of it, y<=(-2x+4)

Answer:

D. y - 7 = 11(x - 5)

Step-by-step explanation:

Use point slope form, y - y1 = m(x - x1), where m is the slope and (x1, y1) is a point on the line.

Plug in the given slope and point:

y - y1 = m(x - x1)

y - 7 = 11(x - 5)

So, the correct answer is D. y - 7 = 11(x - 5)

.・。.・゜✭・Srry but which language is this!?

Answer:

y=-4x+2

Step-by-step explanation:

Hi there!

We want to find out which equation represents a line with a slope of -4 and a y intercept of (0,2)

The most common way to write the equation of the line is in slope-intercept form, which is y=mx+b, where m is the slope and b is the y intercept

We have everything we need to plug into the equation, let's just label the values to avoid confusion

m=-4

b=2 (when you substitute the y intercept as b, b is the value of y in the point)

Now substitute into the equation

y=-4x+2

Hope this helps!

Answer:

B

Step-by-step explanation:

Use pythagorean theorem

4^2+5^2=AC^2, AC= 6.4

7^2+9^2=CB^2, CB=11.4

Answer:

d = 6 , a₁ = - 6 and a₁₀ = 48

Step-by-step explanation:

The nth term of an arithmetic progression is

[tex]a_{n}[/tex] = a₁ + (n - 1)d

where a₁ is the first term and d the common difference

Given a₃ = 6 and a₇ = 30 , then

a₁ + 2d = 6 → (1)

a₁ + 6d = 30 → (2)

Subtract (2) from (1) term by term to eliminate a₁

4d = 24 ( divide both sides by 4 )

d = 6

Substitute d = 6 into (1)

a₁ + 2(6) = 6

a₁ + 12 = 6 ( subtract 12 from both sides )

a₁ = - 6

Then

a₁₀ = - 6 + (9 × 6) = - 6 + 54 = 48

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

Answer:

d=6

a=-6

Step-by-step explanation:

use the formula for the nth term which is

Tn=a+(n-1)d..you will have to create two equations then solve them as a simultaneous equation

T3=6 and T7=30

T3=a+(3-1)d

6=a+2d........... first equation

T7=a+(7-1)d

30=a+6d.......... second equation

then solve them as a simultaneous equation

a+2d=6

a+6d=30

-4d/-4=-24/-4

d=6

a+2d=6

a+2(6)=6

a=6-12

a=-6

I hope this helps

9514 1404 393

Answer:

  A.  1/2

Step-by-step explanation:

The points on a unit circle are (cos(θ), sin(θ)), where θ is the angle from the +x axis to to the ray from the origin through that point.

If the point is (√3/2, 1/2), then sin(θ) = 1/2.

Answer:

144 = c - 379

Step-by-step explanation:

"144 is the same as 379 less than c"

144 = c - 379

Answer and Step-by-step explanation:

This can be written in an equation like this:

144 = c - 379

The question is saying that 144 is the same answer as the result of 379 less than c (or c minus 379). This is why we equal 144 to the result of c minus 379.

#teamtrees #PAW (Plant And Water)

Answer:

1. 0.5

Step-by-step explanation:

The probability of flipping a coin and landing on heads or tails is 100%. So 3)1 would be incorrect. In probability, we learned that just because something was picked more than once, it does not lower the chances of the thing being picked again. So 5)0 would be incorrect. The chances of getting tails are 50% also 0.5 and the chances of getting heads are 50% also 0.5. So 1 is correct.

There is a 0.5 percent chance that the following coin will land on its side.

Probability refers to potential. A random event's occurrence is the subject of this area of mathematics. The range of the value is 0 to 1.

The sample space, which is typically represented using set notation, contains a list of all the potential ordered outcomes as elements. A sample space with all possible outcomes exists for a series of five fair coin tosses. The example of a fair coin toss is 2*2*2H,T.

{HHHHH,HHHHT,HHHTH,HHTHH,HTHHH........TTTTT} The likelihood that the next coin will land on its side is always equal to It doesn't matter if previous results were TTTTT, HHHHH, or TTHT. The probability that the next number will be a tails is therefore still 0.5 in each of these cases as well as all others.

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Option 4

Verification:-

[tex]\\ \sf\longmapsto x-7y=-49[/tex]

[tex]\\ \sf\longmapsto 7-7(8)=-49[/tex]

[tex]\\ \sf\longmapsto 7-56=-49[/tex]

[tex]\\ \sf\longmapsto -49=-49[/tex]

And

[tex]\\ \sf\longmapsto 10x+9y=142[/tex]

[tex]\\ \sf\longmapsto 10(7)+9(8)=142[/tex]

[tex]\\ \sf\longmapsto 70+72=142[/tex]

[tex]\\ \sf\longmapsto 142+142[/tex]

Hence verified

Answer:

4.

Step-by-step explanation:

1. 8x - y = 48

9x + 10y = 142

8(7) - 8 = 48

9(7) + 10(8) = 143

No

2. 9x - y = 55

8x + 10y = 140

9(7) - 8 = 55

9(7) - 10(7) = -24

No

3. x-6y=-41

8x + 9y = 127

7 - 6(8) = -41

8(7) + 9(8) = 128

No

4. x-7y=-49

10x + 9y = 142

7 - 7(8) = 49

10(7) + 9(8) = 142

Yes