university dean wants to estimate the average number of hours per week that freshman spend studying, and so she plans to take a survey. she wants to be 99% confident that her survey average is within 0.5 hours of the true number of hours. the standard deviation from a previous study is 2.6 hours. how large of a sample should the dean take to ensure this is true?

Answers

Answer 1

The sample  should consist of  180 students at least in order for the dean take to ensure this is true.

since we are provided a standard deviation of 2.6 hours, we need to find the sample size at most of 0.5 hours. Since we know

E = z∗ σ/√n, where z is the score,σ is the standard deviation and n is the sample size. According to this case, z∗ will be 2.576 since the dean wants 99% confidence.  so the sample size will be

n=(z∗σ /E)^2

   = (2.57* 2.6/0.5)^2

  =  179.43 =  180

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Related Questions

Find the slope of the line graphed below.

Answers

Answer:

By counting, we see that the point travels down 3, over 6. This is a slope of -3/6. This then simplifies down to -1/2.

The slope is -1/2

X= 1/2 y= -2/5. X+2y

Answers

Answer:

X= 1/2 y= -2/5. X+2y= -1/5.

The equation of the line passing through the point with coordinates (1/2, -2/5) and having slope -1/2 is:

y = -1/2x + b.

Substituting coordinates of the point in the equation, we get:

-2/5 = -1/2(1/2) + b => b = 1/5.

Therefore, the equation of the line is:

y = -1/2x + 1/5.

Step-by-step explanation:

what are the next 2 terms for the sequence: 1, 8, 27, 64, 125​

Answers

Answer:

216, 343

Step-by-step explanation:

1, 8, 27, 64, 125 ← are perfect cubes , that is

1³ = 1 × 1 × 1 = 1

2³ = 2 × 2 × 2 = 8

3³ = 3 × 3 × 3 = 27

4³ = 4 × 4 × 4 = 64

5³ = 5 × 5 × 5 = 125

continuing the pattern for 6 and 7

6³ = 6 × 6 × 6 = 216

7³ = 7 × 7 × 7 = 343

thus the next 2 terms in the sequence are 216, 343

what is the value of y-coordinate of the solution of the systems of equation 2x+3y=6 and 2x+y=-2

Answers

The value of y-coordinate of the solution of the system of equation

2x + 3y = 6 and 2x + y = -2 is y = 4.

Given, a system of equation

2x + 3y = 6 and 2x + y = -2

On subtracting both the equations, we get

3y - y = 6 - (-2)

2y = 6 + 2

2y = 8

On dividing both the sides by 2, we get

2y/2 = 8/2

y = 4

So, the value of y-coordinate of the solution is y = 4.

Hence, the value of y-coordinate of the solution of the system of equation 2x + 3y = 6 and 2x + y = -2 is y = 4.

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Solve the equation 4.2g+ 5 =2.2g + 11 Find the value of g. b. Explain how you can check that the value you found for g is correct. If your check does not​ work, does that mean that your result is​ incorrect? Explain.

Answers

The value of b in the equation  4.2g+ 5 =2.2g + 11 is g = 3   .

In the question ,

it is given that ,

the equation is  4.2g+ 5 =2.2g + 11

on arranging like terms together , we get

4.2g - 2.2g = 11 - 5

2g = 6

g = 6/2

g = 3

the value of g is = 3 .

to check whether the value g = 3 is correct  ,

we substitute g = 3 , in the equation

4.2(3)+ 5 =2.2(3) + 11

12.6 + 5 = 6.6 + 11

17.6 = 17.6

So , the answer that g = 3 is correct .

Therefore , The value of b in the equation  4.2g+ 5 =2.2g + 11 is g = 3   .

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There are 60 seconds in 1 minute.
Use the drop-down menus to help write the equation that can be used to find the
number of seconds, s, given the number of minutes, m.

Answers

Answer: Answer: 1m = 60s, what is the equation?

Step-by-step explanation: 1 minute = 60 seconds so 60s = 1m

which expression is equivalent to 10q+5

Answers

Answer:

5q+5q+5

Step-by-step explanation:

A parabola can be drawn given a focus of (7,3) and a directrix of y = 5. What can be
said about the parabola?
The parabola has a vertex at
), has a p-value of and it [

Answers

A parabola that have a focus of (7,3) and a directrix of y = 5 has these attributes

The parabola is a vertical parabola and facing down

the vertex of the parabular is v(7, 4)

p value of the parabola = -1

How to describe parabola with  focus of (7,3) and a directrix of y = 5

A parabola refers to  shape that traces equation of the form

ax² + bx + c

The directrix of a parabola refers to a vertical or horizontal line that never touches the parabola and at distance p to the vertex of the parabola., and 2p to the focus of the parabola.

when the directrix is on the y coordinate, the parabola formed is a vertical parabola.

If the value of the directrix is more than the corresponding focus or vertex there will be negative p and the parabola will face downward.

conversely, If the value of the directrix is less than the corresponding focus or vertex there will be positive p and the parabola will face up.

from definition of the directrix we calculate for p

2p = y coordinate of focus - equation of directrix

2p = 3 - 5

2p = -2

p = -1

vertex, v(h, k) compared with f(h, k + p)

h + p = 3

h = 4

therefore vertex is (7, 4)

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K 39b
2. Find the equation of the parabola that is a translation of y=2x²-3x+4.
passes through point (2, -1), and has x= 1 as its axis of symmetry.
Then draw the graph.

Answers

The axis of symmetry has the equation x=2, and the vertex is (2,4). The chart is displayed below.

What is parabola?A quadratic function's graph is a parabola. A parabola, according to Pascal, is a circle's projection.Galileo described the parabolic route that projectiles take as they fall under the influence of uniform gravity. Many bodily movements have a curvilinear course that has the shape of a parabola.In mathematics, a parabola is any planar curve that is mirror-symmetrical and typically resembles a U shape.Here, our goals are to comprehend the origin of the parabola's standard formula, its several standard forms, and its characteristics.

For example,

Find the vertex of y = x^2 - 4x + 8 and sketch its graph.

Solution

Completing the square, we have

y  = x^2 - 4x + 8

= (x-2)^2+4 .

Hence the vertex is (2,4) and the axis of symmetry has equation x=2.

The graph is shown below.

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Carmen tutor hitory. For each hour that he tutor , he earn 30 dollar. Let E be her earning (in dollar) after tutoring for H hour. Write an equation relating E to H. Then ue the equation to find Carmen’ earning after tutoring for 13 hour

Answers

Camron (E) = 20h, she earns $300 for 15 hours.

What is unitary method?The unitary technique involves first determining the value of a single unit, followed by the value of the necessary number of units. What can be values and units.Let's say you go to the store to buy six apples. You are informed by the shopkeeper that he is offering 10 apples for Rs 100. In this instance, the value and the units are the price of the apples.Recognizing the units and values is crucial when using the unitary technique to a problem.Always write the items that need to be computed on the right side and the things that are known on the left side to simplify things. We are aware of the quantity of apples and the amount of money in the aforesaid problem.

acc to our question-

with the help of unitary methodCamron (E) = 20h, she earns $300 for 15 hours.

Hence,Camron (E) = 20h, she earns $300 for 15 hours.

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ƒ(x) = −x² – 10x – 9
Find ƒ(−1)

Answers

Answer: 0

Step-by-step explanation:

ƒ(x) = −x² – 10x – 9

Putting value of x as -1

the function is as followed:

ƒ(-1)  = -(-1)^2  - 10 (-1) - 9

ƒ(-1)  = -1 +10-9

ƒ(-1)  = 9-9

         = 0

PLEASE HELP AND ANSWER THESE QUESTIONS IN DEPTH, WILL GIVE MAX POINTS!!

please go over how you get these answers and explain for 23 and 24

Answers

23.

f(x) is just a function in terms of x.

where it says 4f(2) all that means is 4 times the function when x is 2.

To work it out, you just need to swap all xs with 2 and calculate what that is. That gives you f(2), then multiply that answer by 4 to get 4f(2)

Same thing for g(x). First step swap xs for 6 to get g(6) then multiply answer to get 6g(6). At that point, you should have 2 numbers with no x's and you can minus the f by g.

24. Is about compound interest which means that after each year a new amount is worked out rather than a flat amount for the whole 8 years.

2 ways to tackle it, you could work out 8% of each year but that would require you to work it out 8 times which is time consuming and possible to make errors.

2nd way is much easier in that regard.

Final Answer = Initial Amount * (1 + interest rate)^amount of years.

Answer = 5000*(1+0.08)^8

The volume of a cylinder is V=nr²h. What is r in
terms of h and V? (Solve for r)

Answers

The volume of a cylinder in terms of r is √V/πh.

What is volume?

Volume is defined as the space occupied within the boundaries of an object in three-dimensional space.

Given that, the volume of a cylinder = πr²h

Solving in terms of r,

r = √V/πh

Hence, The volume of a cylinder in terms of r is √V/πh.

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[tex]\frac{bd}{a}[/tex]+c if a=−2, b=3, c=−12, and d=−4.

Answers

Answer:

-6

Step-by-step explanation:

3(-4)/-2+(-12)

=-12/-2+(-12)

=6-12

=-6

​Pre-image​ ABCD is dilated to be ​image​ ​A′B′C′D′​ . The origin is the center of dilation. What scale factor is used to create the dilation? Enter your answer in the box. coordinate plane with two squares. square abcd has vertices a at (1, 2), b at (2, 2), c at (2, 1), and d at (1, 1). square a prime b prime c prime d prime has vertices a prime at (3, 6), b prime at (6, 6), c prime at (6, 3), and d prime at (3, 3).

Answers

Answer:

The scale factor is 3

Step-by-step explanation:

Help me with this question I’ll give highest rating

Answers

The value of [tex]x_4[/tex] = 5.8284.

Given:

An iterative formula:

[tex]x_{n+1} = 19/x_n + 3[/tex]

and [tex]x_1[/tex] = 9

for x_2 n = 1 substitute

[tex]x_{1+1} = 19/x_1 + 3[/tex]

[tex]x_{2} = 19/9 + 3[/tex]

= 19 + 3*9 / 9

= 19+27 / 9

= 46/9

[tex]x_3 = 19/x_2 + 3\\[/tex]

= 19/46/9 + 3

= 19*9 / 46 + 3

= 171+138 / 46

= 309/46

[tex]x_4 = 19/x_3 + 3[/tex]

= 19/309/46 + 3

= 19*46+3*309 / 309

= 1801/309

= 5.8284

Therefore The value of [tex]x_4[/tex] = 5.8284.

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Two angles in triangle PQR are congruent, ∠P and ∠Q; ∠R measures 34.15°. What is the measure of ∠P?

145.85°
57.45°
34.15°
72.925°

Answers

Answer:

  (d)  72.925°

Step-by-step explanation:

You have congruent angles P and Q in triangle PQR, where angle R measures 34.15°. You want to know the measure of angle P.

Angle sum theorem

The angle sum theorem tells you the sum of angles in a triangle is 180°.

  P +Q +R = 180°

  P +P +34.15° = 180° . . . . . substitute equivalents

  2P = 145.85° . . . . . . . . . subtract 34.15°

  P = 72.925° . . . . . . . . divide by 2

The measure of ∠P is 72.925°.

31.95 divided by 36.05
round answer in 2 decimal places

Answers

Answer:

0.89

Step-by-step explanation:

31.95 is about 32

36.05 is about 36

32/36 is 0.888...

rounded is 0.89

Answer:

.89

Step-by-step explanation:

Write the following expression in simplest form.

(4 + 15.6a) − (7 + 3.7a)

Answers

Answer:

19.3a - 3

Step-by-step explanation:

(4 + 15.6a) − (7 + 3.7a) =

4 + 15.6a - 7 + 3.7a =

19.3a - 3

Answer:

[tex] \sf \: 11.9a - 3 [/tex]

Step-by-step explanation:

Now we have to,

→ simplify the given expression.

The expression is,

→ (4 + 15.6a) - (7 + 3.7a)

Let's simplify the expression,

→ (4 + 15.6a) - (7 + 3.7a)

→ 4 + 15.6a - 7 - 3.7a

→ (15.6a - 3.7a) + (4 - 7)

→ (11.9a) + (-3)

→ 11.9a - 3

Hence, the answer is 11.9a - 3.

Add (3 - 5i) (-2 8i). sum of real parts: sum of imaginary parts: i

Answers

The multiple of I is the imaginary portion. It is customary to write z = a + bi, where a represents the real part and b represents the imaginary part, to represent complex numbers. where b is the imaginary part and a represents the real part. Sum of Real parts and sum of imaginary parts i is (1 + 3i) 

Explain about imaginary parts?

A and b are referred to as the "real component" and "imaginary part," respectively, of the complex number z=a+bi. If a=0, the complex number is "purely imaginary," and if b=0, it is a real number.

Real components add up to 1, while imaginary parts add up to 3i.

A complex number is stated in its standard form as z = x + iy, where x represents the real part and y represents the imaginary part because it is connected to the imaginary axis.

Considering the formula (3 - 5i) + (-2 + 8i).

Collect similar phrases into real and fictitious parts as follows: 

= (3 - 5i) + (-2 + 8i)

= (3 - 2 - 5i + 8i)

=(1 + 3i) 

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Evaluate the expression: If x = -25 and y = 10, what is the value of x + y -10

Answers

Evaluating the expression in x = -25 and y = 10 gives the value -25.

How to evaluate the expression?

Here we have the expression:

x + y - 10

And we want to evaluate it in x = -25 and y = 10, this just means that we need to replace the variables in the expression by the correspondent numbers.

Doing that we get:

-25 + 10 - 10

Now we can just simplify this expression:

-25 + 10 - 10 = -25 + (10 - 10) = -25

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10r minus 2r plus 4 minus 7r plus 3

Answers

The answer would be...

R + 7

Step-by-step explanation:

collect like terms

10r - 2r - 7r + 4 - 3 =

= r + 1

For 0 ≤ θ < 2π , what are the solutions to sin2(θ) = 2sin2 (startfraction theta over 2 endfraction)? left-brace 0, startfraction pi over 2 endfraction, startfraction 3 pi over 2 endfraction right-brace left-brace 0, startfraction pi over 2 endfraction, pi right-brace left-brace 0, pi, startfraction 3 pi over 2 endfraction right-brace left-brace startfraction pi over 2 endfraction, pi, startfraction 3 pi over 2 endfraction right-brace

Answers

Solutions for the given expression in the given interval will be {0, π/2, 3π/2}.

What are trigonometric expressions?

Trigonometric identities are, by definition, reciprocal. These formulas show the connections between the sine/cosine functions and tangents.

Refer to the attachment for the Question:

[tex]\sin^2{(\theta)}=2\sin^2{(\frac{\theta}{2})}[/tex]

[tex][2\sin{(\frac{\theta}{2})}\cos{(\frac{\theta}{2})}]^2=2\sin^2{(\frac{\theta}{2})}[/tex]

[tex][4\sin^2{(\frac{\theta}{2})}\cos^2{(\frac{\theta}{2})}]=2\sin^2{(\frac{\theta}{2})}[/tex]

[tex][4\sin^2{(\frac{\theta}{2})}\cos^2{(\frac{\theta}{2})}]-2\sin^2{(\frac{\theta}{2})}=0[/tex]

[tex]2\sin^2{(\frac{\theta}{2})}[2\cos^2{(\frac{\theta}{2})}-1]=0[/tex]

[tex]\sin{(\frac{\theta}{2})}=0[/tex]

[tex]{(\frac{\theta}{2})}=n\pi[/tex]

[tex]\theta=2n\pi[/tex] [Here, n = integer]

[tex]\theta=0,\pi,2\pi,....[/tex]

Therefore,[tex]\theta=0[/tex]  [Since,[tex]0\le \theta < 2\pi[/tex] ]

[tex][2\cos^2{(\frac{\theta}{2})}-1]=0[/tex]

[tex]\cos{\theta}=0[/tex]

[tex]x=\frac{\pi}{2}+\pi n[/tex]  [Here, n = integer]

Therefore,[tex]\theta=\frac{\pi}{2}, \frac{3\pi}{2}[/tex]  [Since, [tex]0\le \theta < 2\pi[/tex]]

Hence, solutions for the given expression will be  {0, π/2, 3π/2}.

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Saul wants to cash a check for $715 at his bank. He has $436 in his bank account. How much more money will he need in his bank account to cash the check?

(Write your answer in $00.00 amounts)

Answers

Answer:
$279

Explanation:
715-436=279

Question Progress
Homework Progress
10/29 Marks
The nth term of a sequence is n² + 20
a) Work out the first three terms of the sequence.
b) How many terms in the sequence are less than 50?

Answers

a) The first three terms of the sequence are 21, 24 and 29.

b) There are 6 terms in the sequence are less than 50.

What is Geometric sequence?

An sequence has the ratio of every two successive terms is a constant, is called a Geometric sequence.

Given that;

The nth term of a sequence is,

⇒ n² + 20

Now,

Since, The nth term of a sequence is,

⇒ n² + 20

First term of the sequence is,

⇒ n² + 20

⇒ 1² + 20

⇒ 1 + 20

⇒ 21

Second term of the sequence is,

⇒ n² + 20

⇒ 2² + 20

⇒ 4 + 20

⇒ 24

Third term of the sequence is,

⇒ n² + 20

⇒ 3² + 20

⇒ 9 + 20

⇒ 29

Thus, The first three terms of the sequence are 21, 24 and 29.

And, The fourth term of the sequence is,

⇒ n² + 20

⇒ 4² + 20

⇒ 16 + 20

⇒ 36

And, The fifth term of the sequence is,

⇒ n² + 20

⇒ 5² + 20

⇒ 25 + 20

⇒ 45

The sixth term of the sequence is,

⇒ n² + 20

⇒ 6² + 20

⇒ 36 + 20

⇒ 56

So, There are 6 terms in the sequence are less than 50.

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Kelsey is going to graph the ordered pairs that are represented by this table on a coordinate plane.

x
–6
–4
3
5
y
–4
–6
–6
0

How many points should appear in Kelsey’s graph?

Answers

According to the given coordinates, there are 4 set of points will appear on the Kelsey’s graph and the graph is attached below.

Coordinates.

Coordinates refers the locations of points on a grid known as the cartesian plane or coordinate plane.

Given,

Kelsey is going to graph the ordered pairs that are represented by this table on a coordinate plane.

Here we need to find the number of points should appear in Kelsey’s graph.

In order to find the number of points, first we have to plot the table vales on the graph.

Once we plotted the values on the graph then the graph is look like the following graph.

While we looking through the graph we have identified that the points are (-6,-4), (-4, -6), (3, -6) and (5, 0) are presented on the graph.

Therefore, there are 4 points are plotted on Kelsey’s graph.

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A van moves with a constant speed of 20
miles per hour. How far can it travel in
1/4 hour?

Answers

The van will travel 5 miles in 1/4 hours, if its speed is 20 miles/hour.

What is speed?Speed is the amount of distance covered in a unit of time.It speaks of the motion of an object.The magnitude of the velocity vector is the scalar quantity known as speed.It lacks a distinct direction.A higher speed indicates a faster rate of movement.If the speed is lower, it is moving more slowly.If something isn't moving at all, it has no speed.The constant velocity of an item moving straight ahead can be calculated using the formula:.r = d / t, andd is the distance traveled, and r stands for rate or speed (often written as v, for velocity).The time required to complete the movement

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What are the factors and multiples of 2000?

Answers

Answer:

The factors of 2000 are 1, 2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, 125, 200, 250, 400, 500, 1000, 2000

&

The multiples of 2000 are 2000, 4000, 6000, 8000, 10000, 12000, 14000, 16000, 18000, 20000, ...

what is 3+1x 4+ (-7)

Answers

0 because of P.E.M.D.A.S. Again not 100% sure

Find the value of r so the line that passes through the pair of points has the given slope.



(12, 10), (−2, r), m=−4

Answers

As per the slope intercept form, the value of r is 66.

Slope intercept form:

In order to find the slope intercept form, we have to use the formula,

y = mx + c

where

(x, y) refers the point

m refers the slope

c refers the y-intercept.

Given,

Here we have the pair of points (12, 10), (−2, r) and the value of slope which is m = -4.

Now, we need to find the value of r.

We know that the general form of the slope intercept form is

y = mx + c

First we have to use the slope and the point (12, 10), to find the intercept of the line,

So, we have to apply the value on the formula, then we get,

10 = -4(12) + c

10 = -48 + c

c = 58

So, the slope intercept form equation is

y = -4x + 58

In order to find the value of r, we have to apply the point (-2,r) on the equation, then we get,

r = -4(-2) + 58

r = 8 + 58

r = 66

Therefore, the value of r is 66.

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