An IQ test is designed so that the mean is 100 and the standard deviation is for the population of normal adults. Find the sample size necessary to estimate the mean IQ score of statistics students such that it can be said with ​% confidence that the sample mean is within IQ points of the true mean. Assume that and determine the required sample size.

Answer:

x = (d - c) / (a - b)

Step-by-step explanation:

Let's simply isolate and solve for the variable x.

ax + c = bx + d

ax - bx + c = d

x (a - b) = d - c

x = (d - c) / (a - b)

Thus, we have expressed x in terms of a,b,c, and d.

Cheers.

:)

The value of x in terms of a,b,c, and d will be x = (d - c) / (a - b).

It is described as the process through which we add, subtract, multiply, and divide numerical values. It has the fundamental operators +, -, ×, and ÷.

The order in which arithmetic operations must be performed in an equation is referred to as PEMDAS. This rule states that operations must be performed as follows: parentheses, exponents, multiplication, or division, followed by addition or subtraction.

It is given that,

ax+c =bx +d

a≠b and c≠d

Rearrange the equation and solve it for the x in the following steps,

ax - bx + c = d

x (a - b) = d - c

x = (d - c) / (a - b)

Thus,the value of x in terms of a,b,c, and d will be x = (d - c) / (a - b).

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Answer:

see below

Step-by-step explanation:

We want where  both inequalities are true

y > -3

-2 >-3  this is true

y ≥ 2/3x -4

-2≥ 2/3*3 -4

-2 ≥ 2 -4

-2≥ -2

This is true

This is is the graph

Answer:

[tex]\boxed{\sf Option \ 3}[/tex]

Step-by-step explanation:

[tex]\sf The \ values \ must \ be \ true \ for \ both \ inequalities.[/tex]

[tex]x = 3\\y = -2[/tex]

[tex]y>-3\\-2>-3\\ \sf True[/tex]

[tex]y\geq \frac{2}{3}x-4 \\ -2\geq \frac{2}{3}(3)-4\\2\geq 2-4\\-2\geq-2 \\ \sf True[/tex]

Answer:

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

Step-by-step explanation:

Given equation: -4x + 5y = 20

Sub. in the values

When x = -5 and y = 0 (-5,0),

[tex] - 4( - 5) + 5(0) = 20 [/tex]

When x = 0 and y = 4 (0,4),

[tex] - 4(0) + 5(4) = 20[/tex]

That's how I would do it, not sure if your school has another method. Hope this helps :)

Answer: x = -5 and y = 4

Step-by-step explanation: its the first option do you need me to exlain how cuz its multiple choice  

Answer: B. 25

Step-by-step explanation:

Given: Total books = 625

Number of books can fit in one box = 25

Now, the number of boxes she need to move all of the books = (Total books) ÷ (Number of books can fit in one box )

= 625÷25

= 25

hence, she requires 25 boxes in order to move all of the books.

So, correct option is B. 25.

Nope, i dont think so

Answer:

no the numbers are infinite

Step-by-step explanation:

Answer:

4 units

Step-by-step explanation:

A transformation is the movement of a point from one position to another position. If a shape is transformed all its points are also transformed. Types of transformations are translation, rotation, reflection and dilation.

If a shape is transformed, the length of its sides and shape remains the same, only the position changes.

If Line segment AB has a length of 4 units. It is translated 1 unit to the right on a coordinate plane to obtain line segment A'B, the length of A'B' remains the same which is 4 unit. To prove this:

Let A be at ([tex]x_1,y_1[/tex]) and B be at ([tex]x_2,y_2[/tex]). The length of AB is:

[tex]AB=\sqrt{(y_2-y_1)^2+(x_2-x_1)^2}[/tex]

If AB is translated to the right by 1 unit the new points are A' at ([tex]x_1+1,y_1[/tex]) and B' at ([tex]x_2+1,y_2[/tex]). The length of A'B' is:

[tex]A'B'=\sqrt{(y_2-y_1)^2+(x_2+1-(x_1+1))^2}=\sqrt{(y_2-y_1)^2+(x_2+1-x_1-1)^2}\\\\A'B'=\sqrt{(y_2-y_1)^2+(x_2-x_1)^2}[/tex]

AB = A'B' = 4 units

Answer:

I know the answer

Step-by-step explanation:

Courtney made 60% of her shots

Answer:

she made a 60%

Step-by-step explanation:

first you do this 3÷5

that gives you .60

inorder to get a percent multiply by 100

that gives you an end result of 60

add the percent sing and your done 60%

hope i helped

Answer:

a

Step-by-step explanation:

answer is a on edg

Answer:

18 outfits

Step-by-step explanation:

To determine the number of outfits available

3 shirts * 3 pairs of pants * 2 pairs of shoes

3*3*2

18

Answer:

1). [tex]\frac{2}{x^{2}-x-12 }=\frac{2}{(x+3)(x-4)}[/tex]

2). [tex]\frac{1}{x^{2}-16 }=\frac{1}{(x-4)(x+4)}[/tex]

Step-by-step explanation:

In this question we have to write the fractions in the factored form.

Rational expressions are [tex]\frac{2}{x^{2}-x-12 }[/tex] and [tex]\frac{1}{x^{2}-16 }[/tex].

1). [tex]\frac{2}{x^{2}-x-12 }[/tex]

Factored form of the denominator (x² - x - 12) = x² - 4x + 3x - 12

                                                                           = x(x - 4) + 3(x - 4)

                                                                           = (x + 3)(x - 4)

Therefore. [tex]\frac{2}{x^{2}-x-12 }=\frac{2}{(x+3)(x-4)}[/tex]

2). [tex]\frac{1}{x^{2}-16 }[/tex]

Factored form of the denominator (x² - 16) = (x - 4)(x + 4)

[Since (a²- b²) = (a - b)(a + b)]

Therefore, [tex]\frac{1}{x^{2}-16 }=\frac{1}{(x-4)(x+4)}[/tex]

Answer:

a = -2

Step-by-step explanation:

f(x)=ax+b

f(2)=1  

f(-3)=11

f(2) = 1   means   2a+b =1

f(-3)=11   means   -3a + b = 11

Subtracting the two equations

-(-3a +b =11) becomes 3a -b = -11   so we can add

2a+b =1

3a - b = -11

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

5a = -10

Divide by 5

5a/5 = -10/5

a=-2

Answer:

800700

Step-by-step explanation:

800000 + 00000 + 0000 + 000 + 00 + 0

000000 + 00000 + 0000 + 700 + 00 + 0

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

= 800700

Answer:

Hey there!

800000+700=800700

Hope this helps :)

Answer: The value of [tex](g - f)(x)=4 .[/tex]

Step-by-step explanation:

Given functions :  [tex]f(x) = x + 4[/tex] and [tex]g(x) = x + 7[/tex]

To find : [tex](g - f)(x)[/tex]

Difference between two functions: [tex](u-v)(x)=u(x)-v(x)[/tex]

Then, [tex](g-f)(x)=g(x)-f(x)[/tex]

[tex]=(x+7)-(x+4)=x+7-x-4\\\\=7-4=3[/tex]

Hence, the value of [tex](g - f)(x)=4 .[/tex]

Answer:

B.y = –2.9x + 13.5 i think dont word me for it

Step-by-step explanation:

Equation of line is y = –2.9x + 13.5 which is correct option(B).

A linear equation is defined as an equation in which the highest power of the variable is always one.

Let y = a + bx, where a is the y-intercept and b is the slope.

[tex]\sum{x} = 1 + 2 + 3 + 4 + 5 = 15[/tex]

[tex]\sum{y} = 11 + 8 + 4+ 1 + 0 = 24[/tex]

[tex]\sum {xy} = 11 + 16 + 12 + 4 + 0 = 43[/tex]

[tex]\sum{x^2} = 1 + 4 + 9 + 16 + 25 = 55[/tex]

[tex]n = 5[/tex]

[tex]b= \dfrac{n\sum{xy}-\sum{x}\sum{y}}{n{\sum{x^2}-(\sum{x}})^2}[/tex]

[tex]b= \dfrac{ 5 (43) - (15) . (24)}{{5 (55) - (15})^2}[/tex]

[tex]b= -2.9[/tex]

[tex]a = \dfrac{25}{5} - (-2.9)\dfrac{15}{5}[/tex]

[tex]a=13.5[/tex]

Hence, equation of line is y = –2.9x + 13.5

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Answer:

[tex]m = -j[/tex], or in this case, [tex]m=-(-7)[/tex]

Step-by-step explanation:

Assuming that Justine's score is represented by [tex]j[/tex] and Meagan's score is represented by [tex]m[/tex], we know that [tex]j[/tex] will always be the opposite of [tex]m[/tex].

To represent opposite, we put a negative sign before the variable.

This makes the current number, even if it's negative, the opposite value.

Let's test it out.

Since Justine's score is -7, substituting it into the equation makes it  [tex]m=-(-7)[/tex]. We know that two negatives make a positive, so [tex]m=7[/tex].

Now let's assume Justine's score is 7. Plugging it into the equation, we get [tex]m=-(7)[/tex]. That's the same thing as [tex]m = -1(7)[/tex], and -1 times 7 is -7.

Hope this helped!

Answer:

[tex]A.\ 16\sqrt3\ cm^2[/tex] is the correct answer.

Step-by-step explanation:

Given that:

Side of an equilateral triangle = 8 cm

To find:

Area of the triangle will be:

[tex]A.\ 16\sqrt3\ cm^2[/tex]

[tex]B.\ \dfrac{32}{3} cm^2[/tex]

[tex]C.\ 48\ cm^2[/tex]

[tex]D.\ 36\sqrt3\ cm^2[/tex]

Solution:

First of all, let us have a look at the formula for area of an equilateral triangle:

[tex]A =\dfrac{\sqrt3}{4}a^2[/tex]

Where [tex]a[/tex] is the side of equilateral triangle and an equilateral triangle is a closed 3 sided structure in 2 dimensions which has all 3 sides equal to each other.

Here, we are given that side, [tex]a=8\ cm[/tex]

Putting the value in formula:

[tex]A =\dfrac{\sqrt3}{4}\times 8^2\\\Rightarrow A =\dfrac{\sqrt3}{4}\times 64\\\Rightarrow A =\sqrt3\times 16\\OR\\\Rightarrow \bold{A =16\sqrt3\ cm^2}[/tex]

Hence, [tex]A.\ 16\sqrt3\ cm^2[/tex] is the correct answer.

Answer:

6 sandwiches to choose from because

3×2 = 6

Answer:

6x + 6 = 32

6x = 32 - 6

6x = 26

divide both sides by 6

6x/6 = 26/6

6x + 6 = 4.35

9x - 9 = 24

9x = 24 + 9

9x = 33

divide both sides by 9

9x/9 = 24/9

9x + 9 = 2.66

9x + 9 = 2.66

Answer: x=3

Step-by-step explanation:

[tex]\frac{32}{24} =\frac{4}{3} \\\\\frac{4}{3}=\frac{6x+6}{9x-9}\\ x=3[/tex]

Answer:

d. 31% of the variance in characters per word is accounted for by words per sentence.

Step-by-step explanation:

The coefficient of determination is the statistical measurement that determines the impact in difference of one variable which is explained by the difference in another variable. It is denoted by [tex]R^{2}[/tex] or R-squared. It helps in predicting the outcome of the event.

Answer:

Question 1 = D) Acute

Question 2 = C)3 feet

Question 3 = D) Obtuse

Question 4 = C)27.73 ft.

Step-by-step explanation:

Question 1: A triangle has sides with lengths 5, 6, and 7. Is the triangle right, acute, or obtuse?

In order to be able to accurately classify that a triangle with 3 given sides is either a right , acute or obtuse angle, we use the Pythagoras Theorem

Where:

If a² + b² = c² = Right angle triangle

If a² +b² > c² = Acute triangle.

If a² +b² < c² = Obtuse triangle.

It is important to note that the length ‘‘c′′ is always the longest.

Therefore, for the above question, we have lengths

5 = a, 6 = b and c = 7

a² + b² = c²

5² + 6² = 7²

25 + 36 = 49

61 = 49

61 ≠ 49, Hence 61 > 49

Therefore, this is an Acute Triangle

Question 2: A 15-foot statue casts a 20-foot shadow. How tall is a person who casts a 4-foot-long shadow?

This is question that deals with proportion.

The formula to solve for this:

Height of the statue/ Length of the shadow of the person = Height of the person/ Length of the shadow of the person

Height of the statue = 15 feet

Length of the shadow of the person = 20 feet

Height of the person = unknown

Length of the shadow of the person = 4

15/ 20 = Height of the person/4

Cross Multiply

15 × 4 = 20 × Height of the person

Height of the person = 15 × 4/20

= 60/20

Height of the person = 3 feet

Therefore, the person is 3 feet tall.

Question 3: A triangle has sides with lengths 17, 12, and 9. Is the triangle right, acute, or obtuse?

In order to be able to accurately classify that a triangle with 3 given sides is either a right , acute or obtuse angle, we use the Pythagoras Theorem

Where:

If a² + b² = c² = Right angle triangle

If a² +b² > c² = Acute triangle.

If a² +b² < c² = Obtuse triangle.

It is important to note that the length ‘‘c′′ is always the longest.

Therefore, for the above question, we have lengths 17, 12, 9

9 = a, 12 = b and c = 17

a² + b² = c²

9² + 12² = 17²

81 + 144 = 289

225 = 289

225 ≠ 289

225 < 289

Hence, This is an Obtuse Triangle.

Question 4: Two friends are standing at opposite corners of a rectangular courtyard. The dimensions of the courtyard are 12 ft. by 25 ft. How far apart are the friends?

To calculate how far apart the two friends are we use the formula

Distance = √ ( Length² + Breadth²)

We are given dimensions: 12ft by 25ft

Length = 12ft

Breadth = 25ft

Distance = √(12ft)² + (25ft)²

Distance = √144ft²+ 625ft²

Distance = √769ft²

Distance = 27.730849248ft

Approximately ≈27.73ft

Therefore, the friends are 27.73ft apart.

Answer:

129 m/s^2

Step-by-step explanation:

The length of a rectangle is increasing at a rate of 9m/s

dL/dt = 9m/s

The width is increasing at a rate of 7m/s

dw/dt= 7m/s

The formular for solving the area of a rectangle is length × width

Therefore, to calculate how fast the rectangle is increasing we will apply the product rule

dA/dt= L × dw/dt + W × dl/dt

= 12×7 + 5×9

= 84+45

= 129m/s^2

Hence the area of the rectangle is increasing at 129m/s^2

Answer:

A.the type 1 error probability is [tex]\mathbf{\alpha = 0.0244 }[/tex]

B. β  = 0.0122

C. β  = 0.0000

Step-by-step explanation:

Given that:

Mean = 100

standard deviation = 2

sample size = 9

The null and the alternative hypothesis can be computed as follows:

[tex]\mathtt{H_o: \mu = 100}[/tex]

[tex]\mathtt{H_1: \mu \neq 100}[/tex]

A. If the acceptance region is defined as [tex]98.5 < \overline x > 101.5[/tex] , find the type I error probability [tex]\alpha[/tex] .

Assuming the critical region lies within [tex]\overline x < 98.5[/tex] or [tex]\overline x > 101.5[/tex], for a type 1 error to take place, then the sample average x will be within the critical region when the true mean heat evolved is [tex]\mu = 100[/tex]

∴

[tex]\mathtt{\alpha = P( type \ 1 \ error ) = P( reject \ H_o)}[/tex]

[tex]\mathtt{\alpha = P( \overline x < 98.5 ) + P( \overline x > 101.5 )}[/tex]

when  [tex]\mu = 100[/tex]

[tex]\mathtt{\alpha = P \begin {pmatrix} \dfrac{\overline X - \mu}{\dfrac{\sigma}{\sqrt{n}}} < \dfrac{\overline 98.5 - 100}{\dfrac{2}{\sqrt{9}}} \end {pmatrix} + \begin {pmatrix}P(\dfrac{\overline X - \mu}{\dfrac{\sigma}{\sqrt{n}}} > \dfrac{101.5 - 100}{\dfrac{2}{\sqrt{9}}} \end {pmatrix} }[/tex]

[tex]\mathtt{\alpha = P ( Z < \dfrac{-1.5}{\dfrac{2}{3}} ) + P(Z > \dfrac{1.5}{\dfrac{2}{3}}) }[/tex]

[tex]\mathtt{\alpha = P ( Z <-2.25 ) + P(Z > 2.25) }[/tex]

[tex]\mathtt{\alpha = P ( Z <-2.25 ) +( 1- P(Z < 2.25) })[/tex]

From the standard normal distribution tables

[tex]\mathtt{\alpha = 0.0122+( 1- 0.9878) })[/tex]

[tex]\mathtt{\alpha = 0.0122+( 0.0122) })[/tex]

[tex]\mathbf{\alpha = 0.0244 }[/tex]

Thus, the type 1 error probability is [tex]\mathbf{\alpha = 0.0244 }[/tex]

B. Find beta for the case where the true mean heat evolved is 103.

The probability of type II error is represented by β. Type II error implies that we fail to reject null hypothesis [tex]\mathtt{H_o}[/tex]

Thus;

β = P( type II error) - P( fail to reject [tex]\mathtt{H_o}[/tex] )

∴

[tex]\mathtt{\beta = P(98.5 \leq \overline x \leq 101.5) }[/tex]

Given that [tex]\mu = 103[/tex]

[tex]\mathtt{\beta = P( \dfrac{98.5 -103}{\dfrac{2}{\sqrt{9}}} \leq \dfrac{\overline X - \mu}{\dfrac{\sigma}{n}} \leq \dfrac{101.5-103}{\dfrac{2}{\sqrt{9}}}) }[/tex]

[tex]\mathtt{\beta = P( \dfrac{-4.5}{\dfrac{2}{3}} \leq Z \leq \dfrac{-1.5}{\dfrac{2}{3}}) }[/tex]

[tex]\mathtt{\beta = P(-6.75 \leq Z \leq -2.25) }[/tex]

[tex]\mathtt{\beta = P(z< -2.25) - P(z < -6.75 )}[/tex]

From standard normal distribution table

β  = 0.0122 - 0.0000

β  = 0.0122

C. Find beta for the case where the true mean heat evolved is 105. This value of beta is smaller than the one found in part (b) above. Why?

[tex]\mathtt{\beta = P(98.5 \leq \overline x \leq 101.5) }[/tex]

Given that [tex]\mu = 105[/tex]

[tex]\mathtt{\beta = P( \dfrac{98.5 -105}{\dfrac{2}{\sqrt{9}}} \leq \dfrac{\overline X - \mu}{\dfrac{\sigma}{n}} \leq \dfrac{101.5-105}{\dfrac{2}{\sqrt{9}}}) }[/tex]

[tex]\mathtt{\beta = P( \dfrac{-6.5}{\dfrac{2}{3}} \leq Z \leq \dfrac{-3.5}{\dfrac{2}{3}}) }[/tex]

[tex]\mathtt{\beta = P(-9.75 \leq Z \leq -5.25) }[/tex]

[tex]\mathtt{\beta = P(z< -5.25) - P(z < -9.75 )}[/tex]

From standard normal distribution table

β  = 0.0000 - 0.0000

β  = 0.0000

The reason why the value of beta is smaller here is that since the difference between the value for the true mean and the hypothesized value increases, the probability of type II error decreases.

Answer:

(a = 1/7 (b = .2 (c = 3/9

Step-by-step explanation:

1/7 = .14

1/4 = .25

3/9 = .33

a & b are lower than 1/4 and c is higher

Answer:

[tex]x> \frac{8}{51} [/tex]

Step-by-step explanation:

[tex]7x - \frac{5}{8} x + 3>4[/tex]

Bring constants to one side, simplify:

[tex] \frac{51}{8} x>4 - 3 \\ \frac{51}{8} x>1 \\ x>1 \div \frac{51}{8} \\ x>1 \times \frac{8}{51} \\ x> \frac{8}{51} [/tex]

*Note that the inequality sign only changes when you divide the whole inequality by a negative number.

Answer:

[tex]x>\frac{8}{51}[/tex]

Step-by-step explanation:

[tex]7x-\frac{5}{8}x+3>4\\\mathrm{Subtract\:}3\mathrm{\:from\:both\:sides}\\7x-\frac{5}{8}x+3-3>4-3\\\mathrm{Simplify}\\7x-\frac{5}{8}x>1\\\mathrm{Multiply\:both\:sides\:by\:}8\\7x\times \:8-\frac{5}{8}x\times \:8>1\times \:8\\\mathrm{Simplify}\\56x-5x>8\\51x>8\\\mathrm{Divide\:both\:sides\:by\:}51\\\frac{51x}{51}>\frac{8}{51}\\\\x>\frac{8}{51}[/tex]

I hope it helps :)

Answer: Vu is 15 years old now.

Step-by-step explanation:

Let present age of WU be x.

Then, the present age of Vu = 3x

Also, After 25 years

Age of Wu = x+25

According to the question:

[tex](x+25)=2(3x)\\\\\Rightarrow\ x+25=6x\\\\\Rightarrow\5x=25\\\\\Rightarrow\ x=5[/tex]

Present age of Vu = 3(5) = 15

Hence, Vu is 15 years old now.

Answer:

j

Step-by-step explanation:j

Answer:

Step-by-step explanation:

y varies direcrtly with √(x+5) wich can be expressed mathematically as:

● y = k*√(x+5)

Let's calculate k khowing that y=4 and x=-1

● 4 = k*√(-1+5)

● 4 = k*√(4)

● 4 = k * 2

● k = 4/2

● k = 2

■■■■■■■■■■■■■■■■■■■■■■■■■■

Let's calculate y khowing that x = 11

● y = k*√(x+5)

● y = 2×√(11+5)

● y = 2× √(16)

● y = 2× 4

● y = 8

Answer:

The value of y is 8.

Step-by-step explanation:

Given that y is directly proportional to √(x+5) so the equation is y = k√(x+5) where k is constant. First, you have to find the value of k with given values :

[tex]y = k \sqrt{x + 5} [/tex]

[tex]let \: x = - 1,y = 4[/tex]

[tex]4 = k \sqrt{ - 1 + 5} [/tex]

[tex]4 = k \sqrt{4} [/tex]

[tex]4 = k(2)[/tex]

[tex]4 \div 2 = k[/tex]

[tex]k = 2[/tex]

So the equation is y = 2√(x+5). In order to find the value of y, you have to substitute x = 11 into the equation :

[tex]y = 2 \sqrt{x + 5} [/tex]

[tex]let \: x = 11[/tex]

[tex]y = 2 \sqrt{11 + 5} [/tex]

[tex]y = 2 \sqrt{16} [/tex]

[tex]y = 2(4)[/tex]

[tex]y = 8[/tex]

Answer:

2

Step-by-step explanation:

The term 3x² has 2 as an exponent, the correct option is C.

Exponents are the base raised by power, it is written in the superscript of a number.

The expression is  3x² +y-5

The term 3x² has 2 as an exponent.

Therefore, the correct option is C.

The missing options are

A.3x2

B. y

A 2

C. -5

D. None of these choices are correct.

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Answer:

3* 10 ^12

Step-by-step explanation:

(5x10^7)(6x10^4)

Multiply the numbers together

5*6 =30

Add the exponents

10^7 * 10 ^ 4 = 10 ^(7+4) = 10 ^11

30 * 10 ^11

But this is not scientific notation since 30 >10

Move the decimal one place to the left and add 1 to the exponent

3* 10 ^12

Answer:

3* 10 ^12

Step-by-step explanation:

Answer:

Steven ate 3 pieces

Step-by-step explanation:

If Johnny ate 3/4 , then Steven at 1 - 3/4  or 1/4

12 * 1/4 = 3

Steven ate 3 pieces

Answer:

3 slices of pizza

Step-by-step explanation:

There are 12 total slices of pizza. In order to find how much Johnny ate, we must multiply 12 by 3/4.

12/1 × 3/4 OR 12 × 0.75 = 9

Johnny ate 9 slices of pizza.

Then, we have to subtract 9 from 12 to determine how many slices Steven ate.

12 - 9 = 3

Steven ate 3 slices of pizza.