-9(m + 2) + 406 - 7m)

Answer:

0.9484 = 94.84% probability that the sample proportion of girls will be greater than 41%

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.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

Suppose 44% of the children in a school are girls.

This means that [tex]p = 0.44[/tex]

Sample of 727 children

This means that [tex]n = 727[/tex]

Mean and standard deviation:

[tex]\mu = p = 0.44[/tex]

[tex]s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.44*0.56}{727}} = 0.0184[/tex]

What is the probability that the sample proportion of girls will be greater than 41%?

This is 1 subtracted by the p-value of Z when X = 0.41. So

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

By the Central Limit Theorem

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

[tex]Z = \frac{0.41 - 0.44}{0.0184}[/tex]

[tex]Z = -1.63[/tex]

[tex]Z = -1.63[/tex] has a p-value of 0.0516

1 - 0.0516 = 0.9884

0.9484 = 94.84% probability that the sample proportion of girls will be greater than 41%

To prove that: (2cosA+1) (2cosA-1) = 2cos2A+1

We try to solve one side of the equation to get the other side of the equation.

In this case, we'll solve the right hand side (2cos2A + 1) of the equation with the aim of getting the left hand side of the equation  (2cosA + 1)(2cosA - 1)

Solving the right hand side: 2cos2A + 1

i. We know that cos2A = cos(A+A) = cosAcosA - sinAsinA

Therefore;

cos2A = cos²A - sin²A

ii. We also know that: cos²A + sin²A = 1

Therefore;

sin²A = 1 - cos²A

iii. Now re-write the right hand side by substituting the value of cos2A as follows;

2cos2A + 1 = 2(cos²A - sin²A) + 1

iv. Expand the result in (iii)

2cos2A + 1 = 2cos²A - 2sin²A + 1

v. Now substitute the value of sin²A in (ii) into the result in (iv)

2cos2A + 1 = 2cos²A - 2(1 - cos²A) + 1

vi. Solve the result in (v)

2cos2A + 1 = 2cos²A - 2 + 2cos²A + 1

2cos2A + 1 = 4cos²A - 2 + 1

2cos2A + 1 = 4cos²A - 1

2cos2A + 1 = (2cosA)² - 1²

vii. Remember that the difference of the square of two numbers is the product of the sum and difference of the two numbers. i.e

a² - b² = (a+b)(a-b)

This means that if we put a = 2cosA and b = 1, the result from (vi) can be re-written as;

2cos2A + 1 = (2cosA)² - 1²

2cos2A + 1 = (2cosA + 1)(2cosA - 1)

Since, we have been able to arrive at the left hand side of the given equation, then we can conclude that;

(2cosA + 1)(2cosA - 1) = 2cos2A + 1

Answer:

[tex]\boxed{\sf LHS = RHS }[/tex]

Step-by-step explanation:

We need to prove that ,

[tex]\sf\implies (2 cosA +1)(2cosA-1) = 2cos2A+1[/tex]

We can start by taking RHS and will try to obtain the LHS . The RHS is ,

[tex]\sf\implies RHS= 2cos2A + 1 [/tex]

We know that , cos2A = 2cos²A - 1 ,

[tex]\sf\implies RHS= 2(2cos^2-1)-1 [/tex]

Simplify the bracket ,

[tex]\sf\implies RHS= 4cos^2A - 2 +1 [/tex]

Add the constants ,

[tex]\sf\implies RHS= 4cos^2-1 [/tex]

Write each term in form of square of a number ,

[tex]\sf\implies RHS= (2cos^2A)^2-1^2 [/tex]

Using (a+b)(a-b) = a² - b² , we have ,

[tex]\sf\implies RHS= (2cosA+1)(2cosA-1) [/tex]

This equals to LHS , therefore ,

[tex]\sf\implies \boxed{\pink{\textsf{\textbf{ RHS= LHS }}}} [/tex]

Hence Proved !

Answer:

$40,000

Step-by-step explanation:

this the workings above

Answer:

[tex] g(x)=-8|x |+1. = 9552815 \geqslant 6[/tex]

Answer:

5

Step-by-step explanation:

took the test

The coordinates of the point that divides the line segment from J to K into a ratio of 2:3 are P(-5,7), and the y-coordinate is 7, the correct option is D.

Ratio is described as the comparison of two quantities to determine how many times one obtains the other. The proportion can be expressed as a fraction or as a sign: between two integers.

We are given that;

Ratio= 2:3

Now,

Let the point we are looking for be denoted as P(x,y), and let the ratio be 2:3, which means that the distance from J to P is 2/5 times the distance from J to K.

Using the distance formula, we can find the distance between J and K as:

d = sqrt((x2-x1)^2 + (y2-y1)^2)

= sqrt((-8 - (-3))^2 + (11 - 1)^2)

= sqrt(25 + 100)

= sqrt(125)

The distance from J to P is 2/5 of the total distance, which is:

(2/5)d = (2/5)sqrt(125) = 2sqrt(5)

Using the ratio formula, we get:

x = (3* (-3) + 2 * (-8)) / (3+2) = -5

y = (31 + 211) / (3+2) = 7

Therefore, by the given ratio answer will be 7.

Learn more about the ratio here:

brainly.com/question/13419413

#SPJ7

Answer:

is 22

Step-by-step explanation:

Answer:

It doesn't have a slope?

Step-by-step explanation:

Knowing that the slope equation is y2-y1/x2-x1

9-4       5

----- = ------   = 0

4-4       0

this means that the slope is 0...

Step-by-step explanation:

x intercept=(-1,0) because the graph is passing this point on the x axis

y intercept=(0,-3)

Answer:

4th option

Step-by-step explanation:

The x- intercept is where the graph crosses the x- axis.

This is at (- 1, 0 )

The y- intercept is where the graph crosses the y- axis.

This is at (0, - 3 )

Answer:

[tex]4 {x}^{2} - 4x - 8 - (2 {x}^{2} + 3x - 6) = 4 {x}^{2} - 4x - 8 - 2 {x}^{2} - 3x + 6 = 2 {x}^{2} - 7x - 2[/tex]

Answer:

7x+y=-3

Step-by-step explanation:

if m is the slope of a line, then the slope of its parallel line will have the same slope m,

in the given equation, y=-7x-8, the slope is -7

among the options, 1st option has a slope of -7, since,

7x+y=-3

or, y=-7x-3

Answered by GAUTHMATH

Answer:

Step-by-step explanation:

slope = (y2 - y1)/(x2 - x1)

x2 = -3

x1 = 1

y2 = 1

y1 = - 11

slope = (1 - - 11) / (-3 - 1)

slope = 12 / - 4

slope = - 3

Answer

$0.1346

Explanation:

Find probability of each card and the value of each card and then add them together.

Probability of getting a heart = 13/52

Price of one heart =$0.30

Pay for one heart = 13/52×0.30=$0.075

Probability of getting a queen =4/52

Price of one queen =$0.55

Pay for one queen =4/52×$0.55=$0.0423

Probability of getting a queen of hearts =1/52

Price of one queen =$0.90

Pay for one queen =1/52×$0.90=$0.0173

Therefore the pay for one draw= $0.075+$0.0423+$0.0173=$0.1346

Answer:

scale factor 5:2

x= 27.5

y=12

z=7.5

Step-by-step explanation:

Answer:

HEY THERE!

Step-by-step explanation:

the correct answer for your question is 90°

Answer:

The answer is c :)

Step-by-step explanation:

90 degrees

Answer:

1 mile per 10 minutes

Step-by-step explanation:

Answer:

22 mi

Step-by-step explanation:

From the question given above, the distance from E to F is 6 in.

Thus, we can obtain the distance from E to F (i.e mi) by using the scale provided in the question. This is illustrated below:

3 in = 11 mi

Therefore,

6 in = 6 in × 11 mi / 3 in

6 in = 22 mi

Therefore, the distance from E to F is 22 mi

Answer:

hope this will help you a lot

Answer:

A: x = 0

B: x = All real numbers

Step-by-step explanation:

A.

Any number to the power of (0) equals one. This applies true for the given situation; one is given an expression which is as follows;

[tex](6^2)^x=1[/tex]

Simplifying that will result in;

[tex]36^x=1[/tex]

As stated above, any number to the power of (0) equals (1), thus (x) must equal (0) for this equation to hold true.

[tex]36^0=1\\x=0[/tex]

B.

As stated in part (A), any number to the power (0) equals (1). Therefore, when given the following expression;

[tex](6^0)^x=1[/tex]

One can simplify that;

[tex]1^x=1[/tex]

However, (1) to any degree still equals (1). Thus, (x) can be any value, and the equation will still hold true.

[tex]x=All\ real \ numbers[/tex]

Step-by-step explanation:

Let us take a nominal square of area 25 cm².

So, in this question, we can say that:-

a. The length of one of its sides will be less than 5 cm.

b. Its perimeter will be less than 20 cm.

Hope it helps :)

Step-by-step explanation:

area= 25cm squared

length of one side = 5cm as 5*5 =25

perimeter= 5*4= 20cm

But since the area is less than 25cm squared

we can say that the length of one side is less than 5cm and we can also say that the length of the perimeter is less than 20cm.

Hope this helps.

1...  > equivalent                                                                                                                 2...>equivalent                                                                                                                               3...>not equivalent                                                         mark if u want

Answer:

1/3

Step-by-step explanation:

when you change the mixed numbers to improper fractions, you get 4/5 * 10/9 ÷ 8/3. you can flip the 8/3 to 3/8 and change the division sign to multiplication, because dividing by a fraction is the same as multiplying by its reciprocal. you can cancel some things and ultimately you get 1/3

Step-by-step explanation

n^3-n.

Hope this will help you :) <3

Answer:

8 + 30 ÷ 2 + 4  = 27

8 + 30 ÷ (2 + 4 ) = 13

(8 + 30) ÷ 2 + 4  = 23

Step-by-step explanation:

Solution :

Given :

[tex]f(x) = \left\{\begin{matrix}\frac{1}{450}(x^2-x) & \text{if } 6 < x < 12 \\ 0 & \text{otherwise}\end{matrix}\right.[/tex]

1. Cumulative distribution function

[tex]$P(X \leq x) = \int_{- \infty}^x f(x) \ dx$[/tex]

              [tex]$=\int_{- \infty}^6 f(x) dx + \int_{6}^x f(x) dx $[/tex]

             [tex]$=0+\int_6^x \frac{1}{450}(x^2-x) \ dx$[/tex]

             [tex]$=\frac{1}{450} \int_6^x (x^2-x) \ dx$[/tex]

             [tex]$=\frac{1}{450}\left[\frac{x^3}{3}-\frac{x^2}{2}\right]_6^x$[/tex]

             [tex]$=\frac{1}{450}\left[ \left( \frac{x^3}{3} - \frac{x^2}{2}\left) - \left( \frac{6^3}{3} - \frac{6^2}{2} \right) \right] $[/tex]

            [tex]$=\frac{1}{450}\left[\frac{x^3}{3} - \frac{x^2}{2} - 54 \right]$[/tex]

2.  Mean [tex]$E(x) = \int_{- \infty}^{\infty} \ x \ f(x) \ dx$[/tex]

                       [tex]$=\int_{6}^{12}x . \left( \frac{1}{450} \ (x^2-x)\right)\ dx$[/tex]

                     [tex]$=\frac{1}{450} \int_6^{12} \ (x^3 - x^2) \ dx$[/tex]

                     [tex]$=\frac{1}{450} \left[\frac{x^4}{4} - \frac{x^3}{3} \right]_6^{12} \ dx$[/tex]

                     [tex]$=\frac{1}{450} \left[ \left(\frac{(12)^4}{4} - \frac{(12)^3}{3} \right) - \left(\frac{(6)^4}{4} - \frac{(6)^3}{3} \right) $[/tex]

                     [tex]$=\frac{1}{450} [4608 - 252]$[/tex]

                    = 17.2857

Answer:

11 hours is right answer i hope it will help you

9514 1404 393

Answer:

Step-by-step explanation:

Consecutive interior angles are supplementary.

  (x -20)° +(4x +15)° = 180°

  5x = 185 . . . . . . . . . . . . . . divide by °, add 5

  x = 37 . . . . . . . . . . . . divide by 5

__

  74° +(5y -4)° = 180°

  5y = 110 . . . . . . . . . . . divide by °, subtract 70

  y = 22 . . . . . . . . . . divide by 5

Answer:

≤ y ≤ 70 and 0 ≤ x ≤ 500

Step-by-step explanation:

In this relation we have two things to analyze, the number of gallons of water in the heater, that is 500 gallons, and the time that it took to empty the heater.

Let's count the time.

First, there are 20 minutes in wich 100 gallons are drained.

then, another drain valve is opened, so in 20 minutes they drain 200 gallons of water.

now, the wait for 10 minutes.

Now there are 200 gallons remaining, so the workers must wait for the other 20 minutes to drain the 200 gallons remaining.

The total amount of time is 70 minutes.

So if we have a relationship of water in the heater vs time, where X is the water remaining and Y is the time, the correct domains are:

Y from 0 minutes to 70 minutes

X from 0 gallons to 500 gallons  

So the correct options are C and E.

0 ≤ y ≤ 70 and 0 ≤ x ≤ 500

Step-by-step explanation:

x²-xy-xy+y²

x²+2xy+y²

hope it helps

Answer:

[tex]3\frac{4}{5}[/tex]

Step-by-step explanation:

Hi there!  

»»————-　★　————-««

I believe your answer is:  

[tex]3\frac{4}{5}[/tex]

»»————-　★　————-««  

Here’s why:  

⸻⸻⸻⸻

[tex]\boxed{\text{Calculating the answer...}}\\\\8\frac{1}{5}-4 \frac{2}{5}\\-------------\\\text{Converting the mixed numbers into improper fractions...}\\\\\rightarrow 8\frac{1}{5} =\frac{41}{5}\\\\\rightarrow 4\frac{2}{5}=\frac{22}{5} \\-------------\\\frac{41}{5} -\frac{22}{5}\\\\\rightarrow\boxed{ \frac{19}{5}}\\-------------\\\\text{5 would go into 19 3 times with 4 as the remainder.}\\\\\frac{19}{5}=\boxed{3\frac{4}{5}}\\-------------\\\text{\textbf{Therefore:}}\\\\[/tex]

[tex]8\frac{1}{5}-4\frac{2}{5}=\boxed{3\frac{4}{5}}[/tex]

⸻⸻⸻⸻

»»————-　★　————-««  

Hope this helps you. I apologize if it’s incorrect.  

Answer:

$40,000

Step-by-step explanation:

If 5 breads cost $100, then 1 bread will cost 100/5=20.

So if 1 bread cost $20, then 2000 breads will cost 2000*20=$40,000.

Answer:

$40000

Step-by-step explanation:

5 breads=$100

1 bread=$100/5=$20

2000 breads= $20 x 2000 = $40000

Answer:

Median: 7.5

Mean: 8.6

Step-by-step explanation:

Median = the average of the 2 middle numbers of the set in ascending order, 6, 6, 6, 7, 8, 10, 12, 14

(7+8)/2 = 2

Mean = the sum of the numbers divided by the number of values

6 + 6+ 6+ 7 +8 +10 +12 +14/8

69/8

8.625