What is the minimum sample size required to estimate a population mean with 90% confidence when the desired margin of error is 1.25

Answer:

False

Step-by-step explanation:

We also need to show that it is true for n=1

and for n=k+1

Answer:

  find the difference of points on the graph

Step-by-step explanation:

The cumulative frequency graph (CDF) represents the integral of the probability distribution function (PDF). You find the probability that X is in some interval by subtracting the value of the CDF at the low end of the interval from the CDF value at the high end of the interval.

  p(a < x < b) = cdf(b) -cdf(a)

Answer:

[tex]\pi[/tex] radian

Step-by-step explanation:

We know that angle for a full circle is 2[tex]\pi[/tex]

In the given figure shape is semicircle

hence,

angle for semicircle will be half of angle of full circle

thus, angle for given figure = half of  angle for a full circle = 1/2 * 2[tex]\pi[/tex] = [tex]\pi[/tex]

Thus, answer is [tex]\pi[/tex] radian

alternatively, we also know that angle for a straight line is 180 degrees

and 180 degrees is same as [tex]\pi[/tex] radian.

Step-by-step explanation:

( secA + 1)( sec A - 1)

Using the expansion

( a + b)( a - b) = a² - b²

Expand the expression

We have

sec²A + secA - secA - 1

That's

sec² A - 1

From trigonometric identities

So we have the final answer as

As proven

Hope this helps you

Step-by-step explanation:

Here,

LHS

= (SecA+1)(secA -1)

[tex] = {sec}^{2} A - 1[/tex]

[tex]{as{a}^{2} - {b}^{2} =(a + b)(a - b)[/tex]

Now, we have formula that:

[tex] {sec}^{2} \alpha - {tan \alpha }^{2} = 1[/tex]

[tex] {tan}^{2} \alpha = {sec }^{2} \alpha - 1[/tex]

as we got ,

[tex] = {sec}^{2} A- 1[/tex]

This is equal to:

[tex] = {tan}^{2} A[/tex]

= RHS proved.

Hope it helps....

Answer:

Your question lacks some parts attached below is the complete question

Answer : 2.66

Step-by-step explanation:

The expected number ( E ) can be calculated using the formula below

[tex]E = \frac{row total * column total }{gross total}[/tex]

since we are computing the number of subjects that would prefer Linux operating system and are also rated as exceptional

The row total to be used = 53 ( row total of exceptional )

The column total to be used  = 13 ( column total of Linux )

The gross total to be used = summation of row total of both exceptional and no-exceptional = 259

BACK TO THE EQUATION

E = [tex]\frac{53*13}{259}[/tex]  = 689 / 259

E = 2.6602 ≈ 2.66

Answer:

2009

Step-by-step explanation:

A deficit would be the least amount coming in (Revenues). and the most going out (Expenditures).  So you look for the biggest gap. It appears the gap is largest in 2009.

Answer:

277°

Step-by-step explanation:

The measure of arc AEG = AB + BE + EF + FG

The central angle is congruent to the arc that subtends it

∠ ECB = 180° - 44° = 136° ( adjacent angles )

∠ECF = ∠ ACB = 44° ( vertical angles ), thus

AEG = 44° + 136° + 44° + 53° = 277°

Answer:

Kindly check explanation

Step-by-step explanation:

Taking a careful look at the graph above, the graph depicts that there is sizeable growth or increase in the rate of interest between 2008 to 2012. However, the actual increase in the rate of interest between 2008 - 2012 is (3.152% - 3.141%) = 0.011%. This change is very small compared to what is portrayed by the pictorial representation of the bar graph. This could be due to the scaling of the vertical axis which didn't start from 0, thereby exaggerating the increase in the actual rate of interest. It will thus mislead observers into thinking the increase is huge.

Answer:

170

Step-by-step explanation:

3(4)³ - 2(4)² + 10

192 - 32 + 10 = 170

Answer:

Z > ± 1.645

z= 3.968

Step-by-step explanation:

We formulate the null and alternate hypotheses as

H0 =μ2 ≥ μ1   Ha: μ2  <μ1  one sided

Let α= 0.05

Since the sample sizes are large therefore the test statistic used under H0 is

The critical region for α= 0.05 for a one tailed test Z > ± 1.645

Z = (x`2- x`1) /s/ √n

Z= 154.8-128.746.5/√50

z= 26.1/6.577

z= 3.968

Since the calculated value of z lies in the critical region we reject H0 that internet users spend more time  or equal time.

Answer:

The correct option is b.

Step-by-step explanation:

The complete question is:

Suppose you want to study the length of time devoted to commercial breaks for two different types of television programs. Identify the types of programs you want to study (e.g., sitcoms, sports events, movies, news, children's programs, etc.). How large should the sample be for a specified margin of error.

(a) It depends only on the specified margin of error.

(b) It depends on not only the specified margin of error, but also on the confidence level.

(c) It depends only on the confidence level.

Solution:

The (1 - α) % confidence interval for population mean is:

[tex]CI=\bar x\pm z_{\alpha/2}\times \frac{\sigma}{\sqrt{n}}[/tex]  

The margin of error for this interval is:

 [tex]MOE=z_{\alpha/2}\times \frac{\sigma}{\sqrt{n}}[/tex]

Then the sample size formula is:

[tex]n=[\frac{z_{\alpha/2}\times \sigma}{MOE}]^{2}[/tex]

The sample size is dependent upon the confidence level (1 - α) %, the standard deviation and the desired margin of error.

Thus, the correct option is b.

The size of the sample 'n' depends on not only the specified margin of error, but also on the confidence level.

Given :

Suppose you want to study the length of time devoted to commercial breaks for two different types of television programs.

The following steps can be used in order to determine the size of the sample be for a specified margin of error:

Step 1 - The formula of the confidence interval is given below:

[tex]\rm CI =\bar{x}+z_{\alpha /2}\times \dfrac{\sigma }{\sqrt{n} }[/tex]

Step 2 - Now, for this interval, the formula of margin of error is given below:

[tex]\rm MOE = z_{\alpha /2}\times \dfrac{\sigma}{\sqrt{n} }[/tex]

Step 3 - Solve the above expression for sample size 'n'.

[tex]\rm n = \left(\dfrac{z_{\alpha /2}\times \sigma}{MOE}\right)^2[/tex]

From the above steps, it can be concluded that the correct option is B) It depends on not only the specified margin of error, but also on the confidence level.

For more information, refer to the link given below:

https://brainly.com/question/13990500

Answer:

12/155

Step-by-step explanation:

Total number of cookies:

Probability of getting a peanut butter cookie at first attempt is 9 out of 31:

Probability of getting a peanut butter cookie at second attempt is 8 out of 30 as one already taken and the total number has changed as well:

Probability of getting 2 peanut butter cookies is the product of each probability we got above:

Answer: 7 mi

Step-by-step explanation: since the distance from bluepoint to Manchester is 12 9/10 mi and you know that bluepoint to Silverstone is 5 9/10 subtract that and you get 7 mi as your answer

Answer:

7 miles

Step-by-step explanation:

Hey there!

Well given BM and BS, we need to subtract them.

12 9 /10 - 5 9/10

9/10 - 9/10 = 0

12 - 5 = 7

Silvergrove to Manchester is 7 miles.

Hope this helps :)

Answer:

$16.43.

Step-by-step explanation:

At the grocery store, you spent $485.72. With 2% cashback, you would get 485.72 * 0.02 = 9.7144 dollars worth of cashback.

At other places, you spend $671.28. With 1% cashback, you would get 671.28 * 0.01 = 6.7128 dollars worth of cashback.

9.7144 + 6.7128 = 16.4272, which is about $16.43 of cashback.

Hope this helps!

The amount of cashback that you earned will be $16.42.

The amount of any product is given as though it was a proportion of a hundred. The ratio can be expressed as a quarter of 100. The phrase % translates to one hundred percent. It is symbolized by the character '%'.

Suppose you earn 2% cash back at grocery stores and 1% on all other purchases. If you spent $485.72 at the grocery store and $671.28 on all other purchases.

The total cashback is calculated as,

⇒ 0.02 x $485.72 + 0.01 x $671.28

⇒ $9.71 + $6.71

⇒ $16.42

More about the percentage link is given below.

https://brainly.com/question/8011401

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Answer:

800:1200 or  2:3

Step-by-step explanation:

400 payed

1200 in total

1200-400=800

800:1200 or 2:3

Answer:

a) Pr(drug user| positive test) = 0.3333

b) The probability that he will failed his first test = 0.9703

c) the probability that he is a drug user since  failed his second drug test

= 0.961165

Step-by-step explanation:

From the given information:

Suppose that 1% of the employees of a certain company use illegal drugs.

Probability of illegal drug user = 0.01

Probability of user that do not use drug = 1 - 0.01 = 0.99

From the person that is a illegal drug user, the company performs random drug tests that return positive results = 0.99

Therefore, the negative result for illegal drug user = 1 - 0.99 = 0.01

However, it also has a 2% false positive rate.

i.e the probability of the user that do not use drug has a positive result of 2% = 0.02

Thus, the probability of the user that do not use drug has a negative result of = 1 - 0.02

= 0.98

We are tasked to answer the following questions.

a) Steve, an employee at the company, has a positive test. What is the probability that he is a drug user?

i.e This employee we are taking about is a drug user and he has a positive test.

Thus;

Pr(drug user| positive test) = [tex]\dfrac{0.99 \times 0.01}{0.99 \times 0.01+ 0.02 \times 0.99}[/tex]

Pr(drug user| positive test) = [tex]\dfrac{0.0099}{0.0099+0.0198}[/tex]

Pr(drug user| positive test) = [tex]\dfrac{0.0099}{0.0297}[/tex]

Pr(drug user| positive test) = 0.3333

b) Knowing he failed his first test, what is the probability that Steve will fail his next drug test?

The probability that he will failed his first test = ((0.01 × 0.01) + (0.99×0.98))

The probability that he will failed his first test = ( 1 × 10⁻⁴ + 0.9702)

The probability that he will failed his first test = 0.9703

c)  Steve just failed his second drug test. Now, what is the probability that he is a drug user?

the probability that he is a drug user since he  failed his second drug test using Bayes theorem can be expressed as:

= [tex]\dfrac{0.01 \times(0.99\times 0.99)}{0.01 \times (0.99 \times0.99)+ 0.99(0.02 \times0.02)}[/tex]

the probability that he is a drug user since failed his second drug test

= [tex]\dfrac{0.01 \times(0.9801)}{0.01 \times (0.9801)+ 0.99(4 \times 10^{-4})}[/tex]

the probability that he is a drug user since  failed his second drug test

= [tex]\dfrac{0.009801}{0.009801+ 3.96 \times 10^{-4}}[/tex]

the probability that he is a drug user since  failed his second drug test

= 0.961165

Answer:

Step-by-step explanation:

In order to find B we must first angle C

To find angle C we use the sine rule

That's

[tex] \frac{ |a| }{ \sin(A) } = \frac{ |c| }{ \sin(C) } [/tex]

From the question

a = 15

A = 70°

c = 14

So we have

[tex] \frac{15}{ \sin(70) } = \frac{14}{ \sin(C) } [/tex]

[tex] \sin(C) = \frac{14 \sin(7 0 ) }{15} [/tex]

[tex]C = \sin^{ - 1} ( \frac{14 \sin(70) }{15} ) [/tex]

C = 61.288

Since we've found C we can use it to find B.

Angles in a triangle add up to 180°

To find B add A and C and subtract it from 180°

That's

A + B + C = 180

B = 180 - A - C

B = 180 - 70 - 61.3

To find b we can use the sine rule

That's

[tex] \frac{ |a| }{ \sin(A) } = \frac{ |a| }{ \sin(B) } [/tex]

[tex] \frac{15}{ \sin(70) } = \frac{ |b| }{ \sin(48.7) } [/tex]

[tex] |b| = \frac{15 \sin(48.7) }{ \sin(70) } [/tex]

b = 11.9921

Hope this helps you

Answer:

3.19 seconds

Step-by-step explanation:

Given:

Phone gets dropped from a Height = 150 ft

To find:

Time taken for the phone to reach the ground = ?

Solution:

First of all, let us learn about the formula of distance in terms of Initial speed u; Time t and Acceleration a:

[tex]s=ut+\dfrac{1}{2}at^2[/tex]

Here the phone is dropped from a height so a = g m/[tex]s^2[/tex] i.e. acceleration due to gravity.

g = 9.8 m/[tex]s^2[/tex]

s = 150 ft

Initial velocity, u = 0

Putting all the values in the formula:

[tex]150=0 t+\dfrac{1}{2}gt^2\\\Rightarrow 50=\dfrac{1}{2}\times 9.8 \times t^2\\\Rightarrow t^2=\dfrac{50}{4.9 }\\\Rightarrow t^2=10.20\\\Rightarrow t = 3.19\ sec[/tex]

So, the time taken is 3.19 seconds.

Answer:

Explained below.

Step-by-step explanation:

The ANOVA and Regression output for an application relating maintenance expense (dollars per month) to usage (hours per week) for a particular brand of computer terminal is provided.

(A)

The estimated regression equation equation is:

[tex]y=6.1092+0.8931x[/tex]

Here,

y = maintenance expense (dollars per month)

x = usage (hours per week) for a particular brand of computer terminal

(B)

Consider the Regression output.

The hypothesis to test whether monthly maintenance expense is related to usage is:

H₀: The monthly maintenance expense is not related to usage, i.e. β = 0.

Hₐ: The monthly maintenance expense is related to usage, i.e. β ≠ 0.

Compute the test statistic as follows:

[tex]t=\frac{b}{S.E._{b}}=\frac{0.8931}{0.149}=5.99[/tex]

Compute the p-value as follows:

[tex]p-value=2\times P (t_{8}<5.99}=0.00033[/tex]

The null hypothesis will be rejected if the p-value is less than the significance level.

p-value = 0.00033 < α = 0.05

Reject the null hypothesis.

(C)

Monthly maintenance expense​ is related to usage.

(D)

Yes, the estimated regression equation provide a good fit.

Since the regression coefficient is significant it can be concluded that the regression equation estimated is a good fit.

From the regression output given, the solution to the questions given are outlined thus ;

1.)

Regression equation :

Hence, the estimated regression equation is;

2.)

We can calculate the T-statistic value thus ;

Hence, the T-statistic is given as ;

[tex] T-statistic = \frac{0.8931}{0.149} = 5.99[/tex]

Pvalue (2 tailed) = 0.00033

Decison Region :

Since 0.00033 < 0.05 ; we reject the Null hypothesis.

3.)

Hence, we conclude that monthly expense is related to usage.

4.)

Since, the correlation Coefficient, β ≠ 0 ; Yes, the correlation provides a good fit as it is significant.

Learn more :https://brainly.com/question/18558175

Answer:

1260

Step-by-step explanation:

(7!)/ (2!times 2!)

7 factorial divided by 2factorial times 2 facotiral

The number of distinguishable ways the letters of the following word can be arranged 'MILLION' is 1260.

The different arrangements which can be made out of a given number of objects by taking out some or all at a time are called permutations.

The number of different permutations of n objects with m₁ repeated items, m₂ repeated items,...,mₙ repeated items can be calculated as;

m!/(m₁!)(m₂!)...(mₙ!)

Here, the letter of the word 'MILLION' is a total of 7 letters.

So, the number of possible arrangements will be

(7!)/ (2!times 2!)

= 1260

Therefore the number of distinguishable ways the letters of the following word can be arranged 'MILLION' is 1260.

Learn more about permutations here -

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Answer:

x = 4

Step-by-step explanation:

2( 3x + 3) = 8x - 2

6x + 6 = 8x -2

6x + 8 = 8x

8 = 2x

4 = x

It is given that Y is the midpoint of XZ. If XZ = 8x − 2 and YZ = 3x + 3, So the value of x is x = 4.

Midpoint, as the word suggests, means the point which lies in the middle of something.

Midpoint of a line segment means a point which lies in the mid of the given line segment.

We have been given that Y is the midpoint of XZ. If XZ = 8x − 2 and YZ = 3x + 3, we need to find x.

We know that;

2(YZ) = XZ  

Substitute in the values

2( 3x + 3) = 8x - 2

Use the Distributive Property

6x + 6 = 8x -2

6x + 8 = 8x

8 = 2x

4 = x

Switch the sides to make it easier to read

x = 4

It is given that Y is the midpoint of XZ. If XZ = 8x − 2 and YZ = 3x + 3, So the value of x is x = 4.

To learn more about the midpoint click below;

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Answer:

√32

Step-by-step explanation:

Answer: {5 ± 2√10, 5 - 2√10}

Step-by-step explanation: First isolate the binomial squared by adding 40 to both sides to get (x - 5)² = 40.

Next, square root both sides to get x - 5 = ± √40.

Notice that root of 40 can be broken down to 2√10.

So we have x - 5 = ± 2√10.

To get x by itself, add 5 to both sides to get x = 5 ± 2√10.

So our answer is just {5 ± 2√10, 5 - 2√10}.

As a matter of form, the number will always come before the

radical term in your answer to these types of problems.

In other words, we use 5 ± 2√10 instead of ± 2√10 + 5.

Answer:

First Attachment : Option A,

Second Attachment : Option C

Step-by-step explanation:

We are given that,

z₁ = [tex]3(\cos ((\pi )/(6))+i\sin ((\pi )/(6)))[/tex] and z₂ = [tex]4(\cos ((\pi )/(3))+i\sin ((\pi )/(3)))[/tex]

Therefore if we want to determine z₁( z₂ ), we would have to find the trigonometric form of the following expression,

[tex]3(\cos ((\pi )/(6))+i\sin ((\pi )/(6)))*4(\cos ((\pi )/(3))+i\sin ((\pi )/(3)))[/tex]

( Combine expressions )

= [tex]12(\cos ( \pi /6+\pi / 3 ) + i\sin (\pi /6 +\pi / 3 )[/tex]

( Let's now add [tex]\pi / 6 + \pi / 3[/tex], further simplifying this expression )

[tex]\frac{\pi }{6}+\frac{\pi }{3} = \frac{\pi }{6}+\frac{\pi 2}{6} = \frac{\pi +\pi 2}{6} = \frac{3\pi }{6} = \pi / 2[/tex]

( Substitute )

[tex]12(\cos ( \pi /2 ) + i\sin ( \pi /2 ) )[/tex]

And therefore the correct solution would be option a, for the first attachment.

______________________________________________

For this second attachment, we would have to solve for the following expression,

[tex]\frac{3\left(\cos \left(\frac{\pi \:}{6}\right)+i\sin \left(\frac{\pi \:}{6}\right)\right)}{4\left(\cos \left(\frac{\pi \:}{3}\right)+i\sin \left(\frac{\pi \:}{3}\right)\right)}[/tex]

From which we know that cos(π/6) = √3 / 2, sin(π/6) = 1 / 2, cos(π/3) = 1 / 2, and sin(π/3) = √3 / 2. Therefore,

[tex]\:\frac{3\left(\cos \left(\frac{\pi }{6}\right)+i\sin \left(\frac{\pi }{6}\right)\right)}{4\left(\cos \left(\frac{\pi }{3}\right)+i\sin \left(\frac{\pi }{3}\right)\right)}:\quad \frac{3\sqrt{3}}{8}-i\frac{3}{8}[/tex]

[tex]\frac{3\sqrt{3}}{8}-i\frac{3}{8} = \frac{3\sqrt{3}}{8}-\frac{3}{8}i[/tex]

Our solution for the second attachment will be option c.

Answer: 250 mi

Step-by-step explanation:

Here we can think in a triangle rectangle:

The distance from Birmingham to Atlanta is roughly 150 mi, and this is one of the cathetus.

And the distance from Birmingham to Nashville is roughly 200 mi, this is the other cathetus of the triangle.

Now, the distance from Atlanta to Nashville will be the hypotenuse of this triangle rectangle.

Now we can apply the Pythagorean's theorem:

A^2 + B^2 = H^2

Where A and B are the cathetus, and H is the hypotenuse:

Then:

H = √(A^2 + B^2)

H = √(150^2 + 200^2) mi = √(62,500) mi = 250 mi

Then the estimated distance from Atlanta to Nashville is 250 mi

Answer:

true

Step-by-step explanation:

Answer:

A

Step-by-step explanation:

The height is always perpinducular to the base. The height here is perpendicular to line segment A.

Answer:

A

Step-by-step explanation:

Answer:

Only one solution.

Step-by-step explanation:

y = 3x +2

y -2x =4

y - 2x = 4

=> y = 2x +4

y = 3x + 2

y = 2x + 4

Since both equations are not the same, so the answer cannot be "infinitely many solutions".

They both intersect each other 1 point, so it cannot be "no solutions".

So the answer is "Only 1 solution".

Answer:

the Sum

hope this helps

Answer:

16

Step-by-step explanation:

[tex]\frac{8}{2} x (2+2) = \frac{8}{2} x 4 = \frac{8 x 4}{2} = \frac{32}{2} = 16[/tex]

Answer: 16

PEMDAS

P: Parenthesis

E: Exponents

M: Multipcaction

D: Divison

A: Addition

S: Subtraction

PEMDAS can be also known as Please Excuse My Dear Aunt Sally

P: (2+2)

E: N/A (There are no exponents)

M: 4×4

D: 8÷2

A: 2+2

S: N/A (There is nothing to subtract)

How did we get 4×4? We divided 8÷2 which got us 4. Then we added 2+2 and we also got 4. Then we multiplied 4×4 which got us 16. That's how 16 is our answer.