if we need to decrease the standard deviation of the sampling distribution by half what do we need to do to the sample size

Answers

Answer 1

Answer:

The answer is below

Step-by-step explanation:

For a normal distributed population with a mean (μ), and a standard deviation (σ), if a sample size of n is selected from the population, the mean of the sample ([tex]\mu_x[/tex]) =  μ and the standard deviation of the sample ([tex]\sigma_x[/tex]) = [tex]\frac{\sigma }{\sqrt{n} }[/tex]

Let the normal distribution population have a standard deviation of σ. If the standard deviation is to be decreased by half, the sample size (n) needed is:

[tex]Using:\\\\\sigma_x=\frac{\sigma}{\sqrt{n} } \\\\but\ \sigma_x=\frac{\sigma}{2}\\\\Hence:\\\\ \frac{\sigma}{2}=\frac{\sigma}{\sqrt{n} }\\\\Divide\ through\ by \ \sigma\ to\ get:\\\\ \frac{1}{2}=\frac{1}{\sqrt{n} }\\\\\sqrt{n}=2\\\\square\ both\ sides:\\\\(\sqrt{n} )^2=2^2\\\\n=4\\\\[/tex]

To decrease the standard deviation of the sampling distribution by half we need a sample size of 4


Related Questions

What is the number based on the list of factors? 1,3,7, __
Please help

Answers

Answer:

21 I think, might be wrong.

2+4x=2(2x+1)
Which statements are true?

Select each correct answer.


There is no value for x that will make the equation true.

The equation is an identity,

The solution is 2.

There are infinitely many solutions.

The equation is a contradiction.

There are no solutions.

The equation is true for all values of x.

Answers

Correct answers:
1. There is no value of X that will make the equation true
2. The equation is an identity
4. There are infinite many solutions
5. The equation a contradiction

Which graph represents this system? 2x-5v=-5 y=-3x+1​

Answers

Answer:

Please check the attached graph.

Step-by-step explanation:

The slope-intercept form of the line equation

[tex]y = mx+b[/tex]

where

m is the slopeb is the y-intercept

Given the system of equations

2x - 5y = -5    --- [Equation 1]

y = -3x + 1​      --- [Equation 2]

converting the equation 1 in the slope-intercept form

2x - 5y = -5

5y = 2x+5

divide both sides by 5

y = 2/5x + 1

Thus, the y-intercept  = 1

Now, please check the attached graph below.

The red line represents the equation  2x - 5y = -5

From the graph, it is clear that the red line has the y-intercept y = 1.

Now, considerng the equation 2

y = -3x + 1​  

comparing with the slope-intercept form of line equation

The y-intercept b = 1

Hence, the y-intercept of the line y = -3x + 1​ is y = 1

The green line represents the equation  y = -3x + 1​  

From the graph, it is clear that the green line has the y-intercept y = 1.

Point of Intersection:

It is clear from the graph:

The red line represents the equation  2x - 5y = -5.The green line represents the equation  y = -3x + 1​.

As both lines meet or intersect at the point (0, 1).

Therefore, the point of intersection of both the lines is:

(x, y) = (0, 1)

As we know that the point of intersection of both the lines represents the solution to the system of equations.

Therefore, (0, 1) on the graph represents the solution to the system of equations.

The graph is attached below.

I need help ASAP no rocky

Answers

Answer:

no rocky

Step-by-step explanation:

Answer:

The answer is C

Step-by-step explanation:

I think it's C and I am always right so it is C! You're welcome!

Certain pieces made by an automatic lathe are subject to three kinds of defects X, Y, Z. A sample of 1000 pieces was inspected with the following results: 2.1% had type X defect. 24% had type Y defect. 2.8% had type Z defect. 0.3% had both type X and type Y defects. 04% had both type X and type Z defects. 0.6% had both type Y and type Z defects. 0.1% had type X, type Y, and type Z defects. Draw a Venn Diagram, then find:
(a) What percent had none of these defects?
(b) What percent had at least one of these defects?
(c) What percent were free of type X and/or type Y defects?
(d) What percent had not more than one of these defects?

Answers

Answer:

a) % age of samples containing none of these defects = 93.9%

b)% age of samples containing at least one of these defects = 6.1%

c) % age of samples free of type X and/or type Y defects = 95.8%

d) %age of samples with not more than 1 defect = 98.9%

Step-by-step explanation:

Data Given:

Number of Samples = 1000

Type X defect = 2.1% = 21 samples

Type Y defect = 2.4% = 24 samples

Type Z defect = 2.8% = 28 samples

Both Type X and Y defect = 0.3% = 3 samples

Both Type X and Z defect = 0.4% = 4 samples

Both Type Y and Z defect = 0.6% = 6 samples

Type X and Y and Z defect = 0.1%  = 1 sample

Venn Diagram is attached in the attachment below. Please refer to attachment for the Venn Diagram.

a) % age of samples containing none of these defects.

Solution:

Number of samples containing none of these defects = Total - Samples with defects

Number of samples containing none of these defects = 1000 - { (Type X) + (Type Y) + (Type Z) - (Both X and Y) - (Both X and Z) - (Both Y and Z) + (All defects X and Y and Z) }

 Number of samples containing none of these defects = 1000 - { (21) + (24) +(28) - (3) -(4) - (6) + (1) }

Number of samples containing none of these defects = 1000 - 61

Number of samples containing none of these defects = 939

% age of samples containing none of these defects = 939/1000 x 100

% age of samples containing none of these defects = 93.9%

b) % age of samples containing at least one of these defects:

We have already calculated this above, number of samples containing at least on of these defects:

number of samples containing at least on of these defects = { (Type X) + (Type Y) + (Type Z) - (Both X and Y) - (Both X and Z) - (Both Y and Z) + (All defects X and Y and Z) }

number of samples containing at least on of these defects = { (21) + (24) +(28) - (3) -(4) - (6) + (1) }  

number of samples containing at least on of these defects = 61

% age of samples containing at least one of these defects = 61/1000 x 100

% age of samples containing at least one of these defects = 6.1%

c) % age of samples free of type X and/or type Y defects.

For this find, we need to find the samples with only Z Type defect.

Number of Samples with Only Z type defects = { (Type Z) - (Both X and Z) - (Both Y and Z) + (All defects X and Y and Z) }

Number of Samples with Only Z type defects = { (28)  -(4) - (6) + (1) }

Number of Samples with Only Z type defects = 19

Now, we also know the number of samples without any defects = 939

Now,

The number of samples free of type X and/or type Y defect = Sum of Number of Samples with Only Z type defects and number of samples without any defects

The number of samples free of type X and/or type Y defect = 19+939

The number of samples free of type X and/or type Y defect = 958

% age of samples free of type X and/or type Y defects = 958/1000 x 100

% age of samples free of type X and/or type Y defects = 95.8%

d) %age of samples with not more than 1 defect:

For this find, we need to find number of samples with only X type and with only type Y and with only type Z.

We have already found the number of samples with only Z type defect = 19

Now,

number of samples with only X type defect = { (Type X) - (Both X and Z) - (Both X and Y) + (All defects X and Y and Z) }

number of samples with only X type defect =  { (21)  -(4) - (3) + (1) }

number of samples with only X type defect =  15

Similarly,

number of samples with only Y type defect =  { (Type Y) - (Both Y and Z) - (Both X and Y) + (All defects X and Y and Z) }

number of samples with only Y type defect =  { (24)  -(6) - (3) + (1) }

number of samples with only Y type defect =  16

For,

samples with not more than 1 defect = number of samples with only Y type defect + number of samples with only X type defect + number of samples with only z type defect + number of samples without any defects

samples with not more than 1 defect = 939 + 16 + 15 + 19

samples with not more than 1 defect = 989

%age of samples with not more than 1 defect = 989/1000 x 100

%age of samples with not more than 1 defect = 98.9%

Other Questions
Please give me the correct answer what are 3 most common Operating systems HELP IM BEGGINGGGGGG HURRY! ASAP!What is Grimaud, Porthos' servant, asked to eat?a.a bootc.a sausageb.a letterd.an apple This week, a new acquaintance offers you an illegal drug. List 3 strategies you could use to avoid using the drug? is water vapor only found in hot water? Questions1) Adonde van los estudiantes que tienen interes en pasatiempos?2)Adonde fue para aprender a bailar?3) Como son los deportes de beisbol y futbol en la Republica Dominican?4) Cuanto tiempo hace que tito particpa en el Coro?5) Por que regresa nicolasa a San Miguel de allende? Paco y yo------ la musica escucharescucahaisescuchamosescucho Mrs. Walters drove 360 miles on 25 gallons of gas. Mr. Walters drove 480 miles on 32 gallons of gas.b. Find the mileage per gallon for Mr. Walters's car.Please explain how you got this answer Find the LCM of 156 and 224.Find the LCM of 156 and 224.Find the LCM of 156 and 224.Find the LCM of 156 and 224.Find the LCM of 156 and 224.Find the LCM of 156 and 224.Find the LCM of 156 and 224.Find the LCM of 156 and 224.Find the LCM of 156 and 224.Find the LCM of 156 and 224.Find the LCM of 156 and 224.Find the LCM of 156 and 224. 1. What is unusual about Young Master Shelby teaching Tom how to write?2. When Mrs. Shelby speaks of this sale of her slaves being a curse from God, her husband accuses of sounding like an abolitionist. Why is that such a harsh accusation?3. What provided the comic relief in Chapter 6.(Pls help they are literary questions for Uncle Toms Cabin)Pls answer ASAP, Im giving away a lot of points for me, since I dont even have that many to begin with. The purpose of a cell phone cover is to protect your phone from impact forces. How does a cell phone case do this? can you please answer this? i dont understand Which of the following does NOT describe a polymer? aPolymers usually form by covalent bond. bPolymers are made of monomers (building blocks). cPolymers are large molecules (macromolecules). dPolymers are broken down by the process of dehydration synthesis. Which graph represents this system? 2x-5v=-5 y=-3x+1 I need help ASAP no rocky IGNORE MY ANSWERS BUT WILL SOMEONE PLEASE HELP ME!!!!!!!!!!!! 15 POINTS ON THIS QUESTION What is the inverse function of 4. Write each Radical in Simplified Form (No Decimals.)A) V28B) 500C) 7162 What is the number based on the list of factors? 1,3,7, __Please help