Help only #31,33, please thank you

[tex]\\ \sf\longmapsto \frac{5}{ \sqrt{7} - \sqrt{3} } + \frac{1}{ \sqrt{7} + \sqrt{3} } \\ \\ \sf\longmapsto \frac{5( \sqrt{7} + \sqrt{3} ) + 1 (\sqrt{7} - \sqrt{3} )}{( \sqrt{7} - \sqrt{3} )( \sqrt{7} + \sqrt{3} )} \\ \\ \sf\longmapsto \frac{5 \sqrt{7} + 5 \sqrt{3} + \sqrt{7} - \sqrt{3} }{( { \sqrt{7} )}^{2} - ( \sqrt{3}) {}^{2} } \\ \\ \sf\longmapsto \frac{5 \sqrt{7} + \sqrt{7} + 5 \sqrt{3} - \sqrt{3} }{7 - 3} \\ \\ \sf\longmapsto \frac{6 \sqrt{7} + 4 \sqrt{3} }{4} [/tex]

Answer:

0.9922 = 99.22% probability that the mean monitor life would be greater than 81.2 months in a sample of 146 monitors.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem establishes 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 [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

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

The production manager claims they have a mean life of 83 months with a variance of 81.

This means that [tex]\mu = 83, \sigma = \sqrt{81} = 9[/tex]

Sample of 146:

This means that [tex]n = 146, s = \frac{9}{\sqrt{146}}[/tex]

What is the probability that the mean monitor life would be greater than 81.2 months in a sample of 146 monitors?

This is 1 subtracted by the p-value of Z when X = 81.2. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{81.2 - 83}{\frac{9}{\sqrt{146}}}[/tex]

[tex]Z = -2.42[/tex]

[tex]Z = -2.42[/tex] has a p-value of 0.0078.

1 - 0.0078 = 0.9922.

0.9922 = 99.22% probability that the mean monitor life would be greater than 81.2 months in a sample of 146 monitors.

Correct option is "multiplying a fraction by a repeating decimal."

Explanation:

Since multiplying a fraction is a rational and repeating decimal is also rational, therefore, it's result is also rational.

Hope it helps you... pls mark brainliest if it helped you

Answer:

C. 10,080

Step-by-step explanation:

We can multiply to find how many minutes there are in 1 day.

24 * 60 = 1,440

Now, we can multiply that value by 7 to find out how many minutes there are in 1 week.

1,440 * 7 = 10,080

Best of Luck!

Answer:

  (3t -7)²

Step-by-step explanation:

We know that the square of a binomial is ...

  (a -b)² = a² -2ab +b²

So, when we see the first and last terms are both perfect squares, we suspect that the trinomial is a perfect square trinomial.

  9t² = (3t)²

  49 = 7²

  -42t = -2(3t)(7) . . . . confirming we have a perfect square

The factorization is ...

  (3t -7)²

Answer:

A) children attended=98 b) students attended=60 c)adults attended=49

Step-by-step explanation:

system%28a%2Bc%2Bx=207%2Cc%2Fa=2%2C5c%2B7x%2B12a=1498%29

Simplify and solve the system.

-

a%2B2a%2Bx=207

3a%2Bx=207

x=207-3aandc=2a

-

The revenue equation can be written in terms of just one variable, a.

10a%2B7%28207-3a%29%2B12a=1498

Solve for a;

use it to find x and c.

FURTHER STEPS

-

10a%2B1449-21a%2B12a=1498

a%2B1449=1498

a=98-49

highlight%28a=49 -------adults

-

c=2a

c=2%2A49

highlight%28c=98 -------children

-

x=207-a-c

x=207-49-98

highlight%28x=60 ---------students

Step-by-step explanation:

area=length×width

2.4=x×1.2

1.2x=2.4

x=2.4÷1.2

x=2

therefore width = 2cm

The length of the rectangle is 2 meters.

We have,

Width of rectangle= 1.2m

Area of rectangle = 2.4 m²

To find the length of a rectangle when given its width and area, you can use the formula:

Length = Area / Width

So, the length rectangle

Length = 2.4 m² / 1.2 m

Length = 2 meters

Therefore, the length of the rectangle is 2 meters.

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Answer:

75 inches

Step-by-step explanation:

with this we use change of subject

V=1/3

Pie=3.14

radius =3

height =8

so therefore

V=1/3 ×3.14×3×3×8

V=75.36

9514 1404 393

Answer:

  A = 108.78°

  a = 11 mi

  b = 7 mi

Step-by-step explanation:

The sum of angles in a triangle is 180°, so the third angle is ...

  A = 180° -38.71° -32.51°

  A = 108.78°

__

The remaining sides can be found from the law of sines.

  a/sin(A) = c/sin(C)

  a = sin(A)·c/sin(C) ≈ 0.946762 × 11.163896

  a ≈ 11 mi

  b = sin(B)·11.163896 ≈ 0.625379 × 11.163896

  b ≈ 7 mi

Answer:

B

Step-by-step explanation:

5³.5^×

simply means

5³×5^×

using indices rule,

multiplication is addition

5 is common

so 5(³+×)

hence 5^3+×

Answer:

17.3

Step-by-step explanation:

14.4 x 1.2

= 17.28

= 17.3 ( approximately )

Answer:

36 is the answer

Step-by-step explanation:

Answer:

36

Step-by-step explanation:

72: 2×2×2×3×3

108: 2×2×3×3×3

180: 2×2×3×3×5

here, common factors are 2,2,3 and 3 ..

so.. HCF: 2×2×3×3

•°•HCF=36 ..

Answer:

I think the answer is B. 65%

Answer:

the ans is 45⁰ BC it is a right angle

Step-by-step explanation:

Is this a trigonometry ratio

9514 1404 393

Answer:

  undefined

Step-by-step explanation:

A rational expression is undefined when its denominator is zero.

Answer:

Step-by-step explanation:

10 = 2*5

35 = 5*7

40 = 2*2*2*5

The number 5 is common to all three  factorisations

So the HCF = 5.

Continued division:

10 and 35:

 10) 35(3

       30

          5)10(2

              10

                0

- so the HCF of 10 and 35 is 5.

10 and 40:

10)40( 4

     40

        0  

So the HCF of 10 and 40 is 10

We found HCF of 10 and 35 is 5 so:

HCF of 10, 35 and 40 is HCF of 5 and 10 which is 5.  

Answer:

(123)(62)=x

Step 1: Simplify both sides of the equation.

7626=x  

Step-by-step explanation:

Have a good day.

Answer:7,626

Step-by-step explanation:The easiest way I do it is by taking the numbers and putting them under each other like this

123

 62

then take the number 2 for example and multiply it by 3 then 20 then 100 and do the same with the 6=60 and heres how I solve it

2 x 3=6      2 x 20=40     2 x 100=200       60 x 3=180     60 x 20=1,200    60 x 100=6,000 now take all the numbers and add them

6+40+200=246

180+1,200+6,000=7,380

7,380+246=7,626

(if this helps in anyway feel free to put brainiest but thats your choice) :) happy to help.

65/100 * x or 0.65 * x

Answer:

8 ten dollar bills

20 fifty dollar bills

Step-by-step explanation:

x = number of 10 dollar bills

y = number of 50 dollar bills

x+y = 28

10x+50y = 1080

Multiply the first equation by -10

-10x -10y = -280

Add this to the second equation

-10x -10y = -280

10x+50y = 1080

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

 40y = 800

Divide by 40

40y/40 = 800/40

y = 20

Now find x

x+y =28

x+20 = 28

x = 28-20

x= 8

Answer:

D.

Step-by-step explanation:

The required inequality is given as x ≥ 100 as the water boils at 100°C and above, Option B is correct.

Inequality can be defined as the relation of the equation containing the symbol of ( ≤, ≥, <, >) instead of the equal sign in an equation.

here,
As given in the question,
Water boils at 100°C and above,
So let x be the temperature of the water,
And according to the condition,
x ≥ 100° C

Thus, the inequality x ≥ 100 is shown in option B.

Thus, the required inequality is given as x ≥ 100 as the water boils at 100°C and above, and Option B is correct.

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Answer:

2×2×3×3

Step-by-step explanation:

Answer:

2×2×3×3

Step-by-step explanation:

36=3×12

12=3×4

4=2×2

=3×3×2×2

Hope this helps! <3

Answer:

(-16.494 ; -3.506)

Step-by-step explanation:

student Prob A Prob B difference, d (A-B)

1 20 35____ - 15

2 30 40 ___ - 10

3 15 20 ___ - 5

4 40 50 __ - 10

Difference, d = -15, -10, -5, -10

Xd = Σd/ n = - 40 / 4 = - 10

Standard deviation of d ; Sd = 4.082

The confidence interval for the difference is given as :

Xd ± Tcritical*(Sd/√n)

Tcritical at 95%; df = n - 1 ; 4 - 1 = 3

Tcritical(0.05, 3)). = 3.182

C.I = -10 ± 3.182(4.082/√4)

C.I = -10 ± 6.494462

C. I = (-16.494 ; -3.506)

z -5 =4

neutralize the left -5 by adding 5 on both sides

z -5 (+5) = 4 (+5)

z = 9

22

Step-by-step explanation:

For simplicity, let

x = teary smiley

y = tongue smiley

z = plain smiley

So now our system of equations is

[tex]x + x + x = 12\:\:\:\:\:\:(1)[/tex]

[tex]y + z + x = 18\:\:\:\:\:\:\:(2)[/tex]

[tex]z + z + y = 22\:\:\:\:\:\:\:(3)[/tex]

[tex]z + y + 2x= ??\:\:\:\:\:\:(4)[/tex]

From Eqn(1), we plainly see that

[tex]3x = 12 \Rightarrow x = 4[/tex]

Now subtract Eqn(2) from Eqn(3) to get

[tex](2z + y) - (y + z + x) = 22 - 18[/tex]

[tex]\Rightarrow z - x = 4[/tex]

But we know that [tex]x = 4[/tex], which then gives us [tex]z = 8.[/tex]

Using the values of [tex]x[/tex] and [tex]z[/tex] in Eqn(2), we find that [tex]y = 6.[/tex] Now that we the values of all the variables, use them in Eqn(3) and we'll get

[tex](8) + (6) + 2(4) = 22[/tex]

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Answer:

  26 players to start; 21 players after 5 withdrew

Step-by-step explanation:

We are told that the withdrawing players did not play against each other, so the total number of games they played was 5×2 = 10. Then the number of games played by the remaining players was 220 -10 = 210. When n players play each other, they play a total of n(n -1)/2 games. Here, that total is 210, so we have ...

  n(n -1)/2 = 210

  n^2 -n = 420 . . . . . . . . .multiply by 2

  (n -1/2)^2 = 420.25 . . . . add 0.25 to complete the square

  n = 1/2 +√420.25 = 0.5 +20.5 = 21 . . . . . square root and add 1/2

The number of participating players after 5 withdrew was 21. There were 26 players to start.

Answer:

graph C

Step-by-step explanation:

Amanda needs to have a score higher than 86 on her final.

That means she can't get lower than 86 (Obviously) but not even an 86.

It has to be higher than 86 for her to pass

Let x represent Amanda's score

[tex]x>86[/tex]

Bolded dots on graphs mean that she can have a 86 but if it's not a bolded dot she can have either higher or lower

Just keep that in mind

The answer will be C. because it describes Amanda's score higher than 86

Answer:

c

Step-by-step explanation:

NA = A + W

By adding one unit to length, we increase the overall area by the width of the rectangle. This is because the formula for the area of a rectangle is A = l x w. So, NA = (l + 1) x w = (l x w) + w = A + w.

Differentiating both sides of

xy = 99

with respect to t yields

x dy/dt + y dx/dt = 0

When x = 11, we have

11y = 99   ==>   y = 9

and we're given that dy/dt = -4 at this point, which means

11 (-4) + 9 dx/dt = 0   ==>   dx/dt = 44/9

Answer:

Since points T, R, and P are all present on plane B, the answer is A.

Points T, R, and P define plane B

We have given that,

A. plane B

B. line e

C. line segment PR⎯⎯⎯⎯⎯⎯⎯

D. plane M

We have to determine the Points T, R, and P, define

A plane is a two-dimensional doubly ruled surface spanned by two linearly independent vectors. The generalization of the plane to higher dimensions is called a hyperplane. The angle between two intersecting planes is known as the dihedral angle.

Since points T, R, and P are all present on plane B, the answer is A

Points T, R, and P define plane B.

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