Seven times a number decreased by three-fourths of the same number is 25. What is the number?

Answer:

0.1587 = 15.87% probability that the average fracture strength of 100 randomly selected pieces of this glass exceeds 14.2.

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 fracture strength of tempered glass averages 14 (measured in thousands of pounds per square inch) and has standard deviation 2.

This means that [tex]\mu = 14, \sigma = 2[/tex]

Sample of 100:

This means that [tex]n = 100, s = \frac{2}{\sqrt{100}} = 0.2[/tex]

What is the probability that the average fracture strength of 100 randomly selected pieces of this glass exceeds 14.2?

This is 1 subtracted by the p-value of Z when X = 14.2. So

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

By the Central Limit Theorem

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

[tex]Z = \frac{14.2 - 14}{0.2}[/tex]

[tex]Z = 1[/tex]

[tex]Z = 1[/tex] has a p-value of 0.8413.

1 - 0.8413 = 0.1587

0.1587 = 15.87% probability that the average fracture strength of 100 randomly selected pieces of this glass exceeds 14.2.

Step-by-step explanation:

3.

1.4191919... = 1405/990

4.

√(2/5) and √(1/2)

Step-by-step explanation:

câu trả lời là trong bức ảnh trên

Answe

SI Si olla amigo lel just spammin here

Step-by-step explanation:

Answer:

225 quarters are easy to loose and who will accept that many quarters

Step-by-step explanation:

Answer:

quarters

You will get more money

Answer:

height = (3x + 3)

Step-by-step explanation:

area of rectangular prism = length *breadth

2x^2 + 3x = length*breadth

volume of a rectangular prism = length * breadth *height

6x^3 + 13x^2 + 6x = (2x^2 + 3x) *height

x(6x^2 + 13x + 6) = x(2x + 3) *height

a nd x gets cancel . So,

(6x^2 + 13x + 6) = (2x + 3) *height

6x^2 + (9 + 4)x + 6 = (2x + 3) *height

6x^2 + 9x + 4x + 6 = (2x + 3) *height

3x(2x +3) +2(2x +3) = (2x + 3) *height

(3x + 2)(2x + 3) = (2x + 3)*height

(3x + 2)(2x + 3) / (2x + 3) = height

(2x + 3 ) of numerator and (2x + 3) of denominator gets cancel

(3x + 3) / 1 = height

(3x + 3) = height

Answer:

Sister's house is 7.5 feet high

Step-by-step explanation:

Given :

     My house = 5  feet

     Sisters house = [tex]1\frac{2}{4}[/tex]  [tex]times[/tex]  [tex]my \ house[/tex]

                           = [tex]\frac{6}{4} \times 5[/tex]

                           [tex]=\frac{30}{4}\\\\=\frac{15}{2}\\\\= 7 . 5 \ feet[/tex]

Answer:

The solution of the graph is at (-3,-8).

Step-by-step explanation:

The given equations are :

-4x+3y=-12

and

-2x+3y=-18

These are the system of equations in two variables.

The graphs for the equations are :

The solution of the graph is at (-3,-8).

Answer:

[tex]cos \theta = \frac{11}{12}[/tex]

Step-by-step explanation:

[tex]sin \theta = \frac{\sqrt{23}}{12} \ , \ tan \theta = \frac{\sqrt{23}}{11}\\\\tan \theta = \frac{sin \theta }{cos \theta }\\\\ \frac{\sqrt{23}}{11} = \frac{\frac{\sqrt{23}}{12} }{cos \theta}\\\\cos \theta = \frac{\frac{\sqrt{23}}{12} }{\frac{\sqrt{23}}{11} }\\\\cos \theta = \frac{\sqrt{23}}{12 } \times \frac{11}{\sqrt{23}}\\\\cos \theta = \frac{11}{12}[/tex]

Answer:

-14/2 , 1/3 and 0.325 are the rational numbers

Answer:

= 56.43

Step-by-step explanation:

= 3.42 × 16.5

= 56.43

Answer:

[tex]y = -4x + 2[/tex]

Step-by-step explanation:

Required

Determine the equation

From the question, we understand that, it is parallel to:

[tex]4x + y -10 = 0[/tex]

This means that they have the same slope.

Make y the subject to calculate the slope of: [tex]4x + y -10 = 0[/tex]

[tex]y = -4x + 10[/tex]

The slope of a line with equation [tex]y =mx + c[/tex] is m

By comparison:

[tex]m = -4[/tex]

So, the slope of the required equation is -4.

The equation is then calculated as:

[tex]y = m(x - x_1) + y_1[/tex]

Where:

[tex](x_1.y_1) = (2,-6)[/tex]

So, we have:

[tex]y = -4(x - 2) -6[/tex]

Open bracket

[tex]y = -4x + 8 -6[/tex]

[tex]y = -4x + 2[/tex]

Answer:

Subtraction, and then division.

Step-by-step explanation:

We would subtract 3 on each side to undo the '3', and then divide by 6 on both sides to isolate 'x'.

[tex]6x+3 = 9\\\\6x + 3 - 3 = 9 - 3\\\\ 6x = 6\\\\\frac{6x=6}{6}\\\\\boxed{x=1}[/tex]

Hope this helps.

To solve the equation 6x + 3 = 9 for x, the operations that must be performed on both sides of the equation in order to isolate the variable x are subtraction and then division.

A linear equation in one variable has the standard form Px + Q = 0. In this equation, x is a variable, P is a coefficient, and Q is constant.

Given that 6x + 3 = 9.

First, we have to separate variable and constants. So, we have to subtract 3 from both sides.

6x + 3 - 3 = 9 - 3

i.e. 6x = 6

Now, to solve this equation, we use division.

x = 6/6 = 1

i.e. x = 1

Therefore, to solve the equation 6x + 3 = 9 for x, the operations that must be performed on both sides of the equation in order to isolate the variable x are subtraction and then division.

Learn more about linear equations here -

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Answer:

77 boxes

Step-by-step explanation:

Take the total number of boxes to be sold and divide by the number of girls in the troop

1000/13

76.92307692

Round up

77

Each girl must sell 77

77*13 =1001

Step-by-step explanation:

the Adjacent = √15²-9²=√225-81=√144=12

sin 0 = 9/15 = 3/5

cos 0 = 12/15 = 4/5

tan 0 = 9/12 = ¾

sec 0 = 15/12 = 5/4

csc 0 = 15/9 = 5/3

cot 0 = 12/9 = 4/3

Answer:

4b mod 12 = 4

Step-by-step explanation:

Since b mod 12 = 7, it implies that there is an integer, m such that

b = 12m + 7.

We desire to find 4b mod 12

So, multiplying b by 4, we have

4b = 4(12m + 7)

4b = 4 × 12 m + 4 × 7

4b = 4 × 12 m + 28

4b = 4 × 12 m + 24 + 4

4b = 4 × 12 m + 12 × 2 + 4

Factorizing 12 out, we have

4b = 12(4m + 2) + 4

Since m is an integer 4m + 2 is an integer since the operation of adding and multiplication is closed for the set of integers.

comparing 4b = 12q + r with 4b = 12(4m + 2) + 4,

q = 4m + 2 and r = 4

So 4b mod 12 = 4, that is the remainder when 4b is divided by 12 is 4.

In this exercise we have to calculate the value of the unknown, so we have:

the value is 4

we know that the equation will be given as:

[tex]b = 12m + 7\\[/tex]

we need to multiply both sides by 4 to become another known equation, like this:

[tex]4b = 4(12m + 7)\\4b = 4 * 12 m + 4 * 7\\4b = 4 * 12 m + 28\\4b = 4 * 12 m + 24 + 4\\4b = 4 * 12 m + 12 * 2 + 4[/tex]

So factoring this equation we will find that:

[tex]4b = 12(4m + 2) + 4[/tex]

Thus, when making a comparison between the two equations, we have that:

[tex]4b = 12q + r \\4b = 12(4m + 2) + 4\\q = 4m + 2\\r = 4[/tex]

See more about factoring at brainly.com/question/6810544

Answer:

third option

Step-by-step explanation:

m(n(x)) =

[tex] \frac{x - 3 + 5}{x - 3 - 1} = \frac{x + 2}{x - 4} [/tex]

the domain of this is R/(4)

so as the third option

The function that has the same domain as (m o n)(x) is

h(x) = 11 / (x - 3)

Option D is the correct answer.

A function has an input and an output.

A function can be one-to-one or onto one.

It simply indicated the relationships between the input and the output.

Example:

f(x) = 2x + 1

f(1) = 2 + 1 = 3

f(2) = 2 x 2 + 1 = 4 + 1 = 5

The outputs of the functions are 3 and 5

The inputs of the function are 1 and 2.

We have,

m(x) = (x + 5)/ (x - 1) and n(x) = x - 3,

Now,

(m o n)(x)

= m (n(x)

= m (x - 3)

= (x - 3 + 5) / (x - 3 - 1)

= (x + 2) / (x - 3)

We can not have x = 3.

So,

The domain can not have x = 3.

From the options,

h(x) = 11 / (x - 3) can not have x = 3.

Thus,

The function that has the same domain as (m o n)(x) is

h(x) = 11 / (x - 3)

Learn more about functions here:

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Answer:

2a. 1/4

2b. 2/8

2c. yes, 1/4 = 2/8 because

2 / 8 = 2 ÷ 2 / 8 ÷ 2 = 1 / 4.

2d. the total number of parts doubled in the denominator, the number of parts represented in the numerator doubled as well.

The operations of division and multiplication are made proportionally to the numerator and denominator.

Answer:

x=3

Step-by-step explanation:

The triangles are similar so we can use ratios to solve

x           4

----- = -----------

4.5        6

Using cross products

6x = 4.5 * 4

6x =18

Divide by 6

6x/6 = 18/6

x = 3

Answer:

a) the work done in propelling a five-ton satellite to a height of 100 miles above Earth is 487.8 mile-tons  

b) the work done in propelling a five-ton satellite to a height of 300 miles above Earth is 1395.3 mile-tons

Step-by-step explanation:

Given the data in the question;

We know that the weight of a body varies inversely as the square of its distance from the center of the earth.

⇒F(x) = c / x²

given that; F(x) = five-ton = 5 tons

we know that the radius of earth is approximately 4000 miles

so we substitute

5 = c / (4000)²

c = 5 × ( 4000 )²

c = 8 × 10⁷

∴ Increment of work is;

Δw =  [ ( 8 × 10⁷ ) / x² ] Δx

a) For 100 miles above Earth;

W = ₄₀₀₀∫⁴¹⁰⁰ [ ( 8 × 10⁷ ) / x² ] Δx

= (8 × 10⁷) [tex][[/tex] [tex]-\frac{1}{x}[/tex] [tex]]^{4100}_{4000[/tex]

= (8 × 10⁷) [tex][[/tex] [tex]-\frac{1}{4100}[/tex] [tex]+\frac{1}{4000}[/tex] [tex]][/tex]

= (8 × 10⁷ ) [ 6.09756 × 10⁻⁶ ]

= 487.8 mile-tons  

Therefore, the work done in propelling a five-ton satellite to a height of 100 miles above Earth is 487.8 mile-tons  

b) For 300 miles above Earth.

W = ₄₀₀₀∫⁴³⁰⁰ [ ( 8 × 10⁷ ) / x² ] Δx

= (8 × 10⁷) [tex][[/tex] [tex]-\frac{1}{x}[/tex] [tex]]^{4300}_{4000[/tex]

= (8 × 10⁷) [tex][[/tex] [tex]-\frac{1}{4300}[/tex] [tex]+\frac{1}{4000}[/tex] [tex]][/tex]

= (8 × 10⁷ ) [ 1.744186 × 10⁻⁵ ]

= 1395.3 mile-tons

Therefore, the work done in propelling a five-ton satellite to a height of 300 miles above Earth is 1395.3 mile-tons

Answer:

Your options are not clear

Step-by-step explanation:

[tex]\sqrt[3]{-1000 \times p^{12} \times q^3} \\\\(-1 \times 10^3 \times p^{12} \times q^3)^{\frac{1}{3} }\\\\(-1^3)^{\frac{1}{3} }\times 10^{3 \times \frac{1}{3} } \times p^{12 \times \frac{1}{3}} \times q^{3 \times \frac{1}{3}} \ \ \ \ \ \ \ \ \ \ \ \ \ \ [ \ (-1)^3 = - 1 \ ] \\\\- 1 \times 10 \times p^4 \times q\\\\-10p^4q[/tex]

9514 1404 393

Answer:

  4 hours 40 minutes

Step-by-step explanation:

The appropriate relation is ...

  time = distance/speed

  time = (3800 km)/(900 km/h) +(400 km)/(900 km/h) = (38+4)/9 h

  = 14/3 h = 4 2/3 h

Seema's flight time is 4 hours 40 minutes.

__

2/3 of 60 minutes is 40 minutes

Since there is a fixed number of trials and the trials are independent, it is appropriate to use the binomial probability distribution to find the probability that a contestant who plays the game that day several times wins exactly 4 times.

The formula is:

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

The parameters are:

In this problem:

Thus, the binomial distribution is appropriate.

You can learn more about the binomial distribution at https://brainly.com/question/24863377

Answer:

Option (A)

Step-by-step explanation:

Sasha has an amount of $400 and saves $20 per week.

If we graph the savings of Sasha, her savings per week will be defined by the slope of the line = $20 per week

Similarly, from the graph attached,

Slope of the line given in the graph = Per week savings of Natalia

Slope of line passing through (0, 190) and (2, 210) will be,

Slope = [tex]\frac{y_2-y_1}{x_2-x_1}[/tex]

          = [tex]\frac{210-190}{2-0}[/tex]

          = 10

Therefore, per week savings of Natalia = $10

Difference in savings of Sasha and Natalia = 20 - 10 = $10 per week

Here, Sasha shows the greater rate of change by $10 per week

Therefore, Option (A) will be the answer.

let the number be b

62.5/100 x b = 25

0.625 x b = 25

b =25/0.625

b=40

half of b= 40/2 = 20

Answer:

[tex]{ \bf{r(t) = 7e {}^{0.6t} }} \\ { \tt{r(2) = 7 {e}^{0.6 \times 2} }} \\ = { \tt{7 {e}^{1.2} }} \\ = 23.241 \: thiusand bacteria \: per \: hour[/tex]