What sample size is needed to give a margin of error within in estimating a population mean with 95% confidence, assuming a previous sample had .

Answers

Answer 1

Answer:

[tex]n = (\frac{1.96\sqrt{\pi(1-\pi)}}{M})^2[/tex]

The sample size needed is n(if a decimal number, round up to the next integer), considering the estimate of the proportion [tex]\pi[/tex](if no previous estimate use 0.5) and M is the desired margin of error.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.

[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

In which

z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].

The margin of error is of:

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

95% confidence level

So [tex]\alpha = 0.05[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].

Needed sample size:

The needed sample size is n. We have that:

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

[tex]M = 1.96\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

[tex]\sqrt{n}M = 1.96\sqrt{\pi(1-\pi)}[/tex]

[tex]\sqrt{n} = \frac{1.96\sqrt{\pi(1-\pi)}}{M}[/tex]

[tex](\sqrt{n})^2 = (\frac{1.96\sqrt{\pi(1-\pi)}}{M})^2[/tex]

[tex]n = (\frac{1.96\sqrt{\pi(1-\pi)}}{M})^2[/tex]

The sample size needed is n(if a decimal number, round up to the next integer), considering the estimate of the proportion [tex]\pi[/tex](if no previous estimate use 0.5) and M is the desired margin of error.


Related Questions

What is a statistical error?

Answers

Answer:

Statistical error is the difference between the estimated or approximated value and the true value.  

Two Possible Types of Statistical Error

Type I Errors occur when we reject a null hypothesis that is actually true; the probability of this occurring is denoted by alpha (a).

Type II Errors are when we accept a null hypothesis that is actually false; its probability is called beta (b).

Example

You test whether a new drug intervention can alleviate symptoms of an autoimmune disease.

A Type I error happens when you get false positive results: you conclude that the drug intervention improved symptoms when it actually didn’t. These improvements could have arisen from other random factors or measurement errors.

A Type II error happens when you get false negative results: you conclude that the drug intervention didn’t improve symptoms when it actually did. Your study may have missed key indicators of improvements or attributed any improvements to other factors instead.

Find cot 0, sec 0, and cos 0, where is the angle shown in the figure. Give exact values, not decimals approximations.

Answers

Answer:

Cot 0 = undefined

Sec0 = cos0 = 1

Step-by-step explanation:

According to trig identity

Cot theta = 1/sin theta

Sec theta = 1/cos theta

Hence

Cot 0 = 1/tan0

Cot 0 = 1/0

Since a/0 is undefined, hence cot 0 will be undefined

Sec 0 = 1/cos 0

Sec0 = 1/1 = 1

Cos 0 = 1

From a standard deck of 52 cards (containing the spades, diamonds, clubs, and hearts suites), what is the probability that you draw the three of squares?

Answers

Answer:

1/52

Step-by-step explanation:

theres 52 cards and there is only one three of squares so there is a 1/52 chance

Answer:

3/52

Step-by-step explanation:

Please help me!!
Complete the truth table for the statement A ∧ ~(B ∧ C).

A B C A ∧ ~(B ∧ C)
T T T
?
T T F
?
T F T
?
T F F
?
F T T
?
F T F
?
F F T
?
F F F
?

Answers

9514 1404 393

Answer:

  see attached

Step-by-step explanation:

The desired expression can be expanded to the sum of products form ...

  A ∧ ¬(B ∧ C) = (A∧¬B) ∨ (A∧¬C)

It will only be true when A is true and one of B or C is false.

In circle A below, chord BC and diameter DAE intersect at F. If arc CD = 46° and arc BE = 78°, what is m_BFE? D B А​

Answers

Given:

Consider the below figure attached with this question.

In circle A below, chord BC and diameter DAE intersect at F.

The arc CD = 46° and arc BE = 78°.

To find:

The measure of angle BFE.

Solution:

According to intersecting chords theorem, if two chords intersect inside the circle then the angle on the intersection is the average of intercepted arcs.

Using intersecting chords theorem, we get

[tex]m\angle BFE=\dfrac{1}{2}(m(arcCD)+m(arcBE))[/tex]

[tex]m\angle BFE=\dfrac{1}{2}(46^\circ+78^\circ)[/tex]

[tex]m\angle BFE=\dfrac{1}{2}(124^\circ)[/tex]

[tex]m\angle BFE=62^\circ[/tex]

Therefore, the measure of angle BFE is 62°.

If you are just given the two points it is the same formula. Find the midpoint between the points (4,-5) and (-4,5)

Answers

mid point =((4+(-4))/2,(-5+5)/2)

=(0,0)

The midpoint between the points (4, -5) and (-4, 5) is (0, 0).

To find the midpoint between two points ([tex]x_1, y_1[/tex]) and ([tex]x_2, y_2[/tex]), you can use the midpoint formula:

Midpoint = [tex]((x_1+ x_2)/2, (y_1+ y_2)/2)[/tex]

In this case, the two points are (4, -5) and (-4, 5).

So, the midpoint using the formula:

[tex]x_1[/tex] = 4

[tex]y_1[/tex] = -5

[tex]x_2[/tex]= -4

[tex]y_2[/tex] = 5

Midpoint

= ((4 + (-4)) / 2, (-5 + 5) / 2)

= (0 / 2, 0 / 2)

= (0, 0)

Therefore, the midpoint between the points (4, -5) and (-4, 5) is (0, 0).

Learn more about midpoint here:

https://brainly.com/question/24089949

#SPJ2

Idek how to explain this but please help me

Answers

Answer:

Put 4 in the place of x then you'll get

[tex] \frac{10}{22} [/tex]

Answer:

[tex]\frac{5}{11}[/tex]

Step-by-step explanation:

→ Substitute 4 for x

[tex]\frac{4^{2}-6 }{(3*4)+10} =\frac{16-6}{12+10} =\frac{10}{22} =\frac{5}{11}[/tex]

.
6.EE.2c
1. Evaluate the following algebraic expression when x = 3
2xexponet2 + 5x - 10

Answers

Answer:

the answer is 23

Step-by-step explanation:

2x9+15-10

18+15-10

33-10

23

`Please help me with this 4/5v = - 8/7

Answers

Answer: v= -10/7


Explanation: Simply both sides of the equation then isolate the variable.

please help I'm not good with word problems ​

Answers

Answer:

7 5/8

Step-by-step explanation:

5+2= 7 3/8+2/8=5/8 7+5/8=7 5/8

5 ²⁄₈+2 ⅜= 7 ⅝
7 ⅝ miles is the answer


Please help.
A: 4/7
B: 3/7
C:5/7
D: 2/7

Answers

Answer:

D: 2/7

Step-by-step explanation:

The probability of an event x is how likely the event will occur. It is given as;

P(x) = number of expected outcomes / number of possible outcomes

Given:

Event A = The place is a city.

Therefore,

P(A) is the probability that the event A happens. i.e the probability that a place is a city.

P([tex]A^c[/tex]) is the probability that the event A does not happen. i.e the probability that a place is not a city

Also,

The sum of the probability that an event happens and the probability that the event does not happen is equal to 1. i.e

P(A) + P([tex]A^c[/tex]) = 1

From the table,

P([tex]A^c[/tex]) is found by counting the number of places that does not have a tick on the "is a city" column, then divide the result by the total number of places. i.e

P([tex]A^c[/tex]) = 2 ÷ 7

P([tex]A^c[/tex]) = 2/7

Therefore P([tex]A^c[/tex]) which is the probability that the place is not a city is 2/7

Which interval would not be used for the stems of a stem-and-leaf plot?
1
5
10
100

PLEASE HELP 100 IS NOT RIGHT

Answers

Answer:

I JUST DID IT ITS 5.

Answer:

5

Step-by-step explanation:

Does someone know the answer too: 10 less than s? Ty

Answers

Answer:

s-10

hope this helps

have a good day :)

Step-by-step explanation:

how can i answered this​

Answers

Here’s the answer, hope you understand

Answer:

hope it is helpful to you

Question 8 of 10
The linearized regression equation for an exponential data set is
log y = 0.23x + 0.8, where x is the number of years and y is the population
What is the predicted population when x - 10? Round your answer to the
nearest whole number.
A. 81,963
B. 200
C. 3
D. 1259

.

Answers

Answer:

log y = 3

Step-by-step explanation:

Substitute 10 for x, obtaining the following:

log y = 0.23(10) + 0.8, or

log y = 2.3 + 0.8, or 3.10, or (to the nearest whole number):

log y = 3

Find all the zeros of f(x) = 2x - 5x² - 4x + 10.

Answers

Answer:

10

Step-by-step explanation:

Plug in 0 where x is

See image below:)

A union of restaurant and foodservice workers would like to estimate the mean hourly wage, , of foodservice workers in the U.S. The union will choose a random sample of wages and then estimate using the mean of the sample. What is the minimum sample size needed in order for the union to be confident that its estimate is within of

Answers

Answer:  the minimum sample size needed = 145

Step-by-step explanation:

Formula for sample size:

[tex]Sample \ size =(\dfrac{z^*\times standard\ deviation}{margin \ of \ error})^2[/tex]

, where z* = Critical z-value

Given: Standard deviation = 2.15

Margin of error = 0.35

Z* for 95% confidence = 1.96

Sample size = [tex](\frac{1.96\times2.15}{0.35})^2[/tex]

[tex]=(12.04)^2\\\\=144.9616\approx145[/tex]

Hence, the minimum sample size needed = 145

Avi's pet hamster Chubby loves to run in his hamster wheel. During one "race", Avi counts 100 rotations of the wheel. She wants to know how far Chubby ran, so she measures the diameter of the wheel and finds that it is 20 cm
How far did Chubby run?
Round your answer to the nearest cm
PLEASE HELP ILL GIVE BRAINLIEST

Answers

9514 1404 393

Answer:

  6283 cm

Step-by-step explanation:

The circumference of the wheel is given by ...

  C = πd

  C = π(20 cm) ≈ 62.83185 cm

100 turns of the wheel will be a distance 100 times this value, or ...

  race = 100C = 100(62.83185 cm) = 6283.185 cm

Chubby ran about 6283 cm.

__

Additional comment

To get the required 4 significant figures in the answer, we used the "pi button" on the calculator. Alternatively, you could use the ratio π ≈ 355/113, which is good for 6 significant figures.

An animal shelter has enough pens for x small dogs and y large dogs, and can hold up to 36 dogs at a time. It costs the shelter $12 a week to keep a large dog and $7 a week to keep a small dog. The shelter must keep its weekly costs under $350. Which system of inequalities can be used to represent this situation?

Answers

Answer:

7x+12y<350

Step-by-step explanation:

7 times each small dog (x) plus 12 times each large dog (y) needs to be less than (<) 350

A positive real number is 2 more than another. If the sum of the squares of the two numbers is 42, find the numbers.

Answers

Answer:

Step-by-step explanation:

From the first sentence x (the number) is 2 more than another number (y). So, x+2=y. The sum of the squares of the two numbers is 42, meaning that [tex]\\ (x+2)^{2}[/tex]+[tex]y^{2}[/tex]=42. First, we square root the ENTIRE equation to get rid of the square. If you do one thing to one side, you have to do it to the other. After this, we have x+2+y=[tex]\sqrt{42}[/tex]. Now, we subtract 2 from the other side to isolate the variable. You can isolate either one but normally I go for x. Now we have x+y=[tex]\sqrt{42}[/tex]+2. Now, we want to get y to the other side so we subtract it from the left side and the right side which gives us x=-y+[tex]\sqrt{42}[/tex]+2. now we know what X is equal to. Now we plug in x for [tex]\\ (x+2)^{2}[/tex]+[tex]y^{2}[/tex]=42, which gives us          [tex](-y+\sqrt42}+2+2)^{2}[/tex]+[tex]y^{2}[/tex]=42. Now we only have one variable which is what we want. Next, we square root the entire thing to get rid of the squares, which gives us -y+[tex]\sqrt{42}[/tex]+4+y=[tex]\sqrt{42}[/tex]. I got lost in my work. I must have done something wrong I cant find out. If anyone wants to pick up where I left off go ahead but there's a timer and I have one minute left. I cant finish the problem in a minute. I'm sorry and hopefully I lead you somewhere.

How to solve the inequality 8x + 10 ≤ 60

Answers

Answer:

x ≤ 6.25

Step-by-step explanation:

8x + 10  ≤  60

Subtract 10 from both sides

8x ≤ 50

Divide both side by 8

x ≤ 6.25

If my answer is incorrect, pls correct me!

If you like my answer and explanation, mark me as brainliest!

-Chetan K

If the mean of a normal distribution is 26, what is the median of the distribution? O A. 22 O B. 14 C. 26 D. 18 SUB​

Answers

Answer:

B

Step-by-step explanation:

26 divides by 2 = 13

13+2=14

can someone please help me solve?

Answers

Answer:

0.75

Step-by-step explanation:

d = FE = 4

e = DF = 3

f = ED = 5

f/sin(F) = e/sin(E)

5/sin(90) = 3/sin(E)

5 = 3/sin(E)

sin(E) = 3/5 =0.6

E = asin(0.6) = 36.869898... degrees

tan(E) = tan(36.869898...) = 0.75

Ralph’s classroom measures 12 meters in length. What is the length of the classroom in millimeters?

A. 11,000 mm
B. 12,000 mm
C. 12,500 mm
D. 13,000 mm

Answers

Answer:

b. 12 000 mm

Step-by-step explanation:

multiply by 1 000

A bookstore helppppppoo

Answers

30% fewer mysteries means it has 70% of the quantity of science fiction:

Mysteries = 120 x 0.70 = 84

They have 84 mystery books.

They have 25 % more biographies than mysteries:

Multiply the number of mysteries by 1 + 25%:

84 x 1.25 = 105

They have 105 biographies

5/6 multiples by 10/11

Answers

Answer:

0.757... (recurring)

Step-by-step explanation:

5                 10                     50

_       x         _           =          _

6                 11                       66

50/66 = 0.757...

:D

Answer:

50/66

Step-by-step explanation:

[tex](\frac{5}{6})(\frac{10}{11}) = \frac{50}{66}[/tex]

Have a great day!

Find the solution of the system of equations.
6x+2y = 16
20 - 2 = 32

HELP PLSSSS

Answers

are there variables in the second equation?

Get brainiest if right!!

Mark has 1.5 times more collectible cards than Jacob. If Mark
gives Jacob 11 cards, they will have the same number of
collectible cards. How many cards do they have?

Answers

Answer:

17.5 cards

Step-by-step explanation:

11 x 1.5 = 16.5

16.5 + 11 = 17.5 cards

Answer:

110

Step-by-step explanation:

Let us take Jack cards as x

Then Mark cards will be 1.5 * x

Mark gives 11 cards to Jack...the equation is

1.5 * x  - 11 = x + 11

Adding +11 on both sides

1.5*x -11 + 11 = x + 11 + 11

1.5*x = x + 22

Subtracting x on both sides

1.5*x - x = x + 22 - x

.5*x = 22

x = 22 * 1/.5 = 220/5 = 44

Now go back to the initial equation

Mark >> 1.5  * x = 66

Jack  >> 1 * x = 44

Total >> 110.

a.-2
b.2
c.1
d.-1
e.-6

plz help being timed will mark brainliest​

Answers

Answer:

-2 and -1

Step-by-step explanation:

The range would be inside the red half circle and since it is below the horizontal middle line, it is negative. Both -1 and -2 are in the range of the red half circle, both of them are the answer

question : Suppose you have VND 100 million to save orspend. If you lend, you will receive 112 million after a year. Inflation is 14% / year.
a. What is the nominal interest rate you get?
b. What is the real interest rate?
c. Should you save or spend that money?
d. Question (c) how will be answered if inflation is 10% / year, nominal interest rates do not change?

Answers

Answer:

Step-by-step explanation:

Other Questions
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