under what conditions is s2p the average of the two sample variances?

Answers

Answer 1

Answer:One way to compare the variability of two populations is to use the pooled variance, which is a weighted average of the two sample variances.

Explanation:The pooled variance is denoted by s2p and it is calculated as follows:

s2p = [(n1 - 1)s12 + (n2 - 1)s22] / (n1 + n2 - 2)

where n1 and n2 are the sample sizes and s12 and s22 are the sample variances. The pooled variance is the average of the two sample variances when the two populations have the same variance and the two sample sizes are equal. In other words, s2p = (s12 + s22) / 2 when σ12 = σ22 and n1 = n2. This is one condition under which s2p is the average of the two sample variances.


Related Questions

Which of these are correct

Answers

Answer:

A

Explanation:

I'm doing that rn and that's the answer

PLEASE HELP!!!

How many kilograms of chlorine gas is needed to produce 45.0 grams of hydrochloric acid?

Answers

Answer:

43.76 g = 0.04376 Kg

Explanation:

The equation of the reaction is given as;

H2 + Cl2 --> 2HCl

From the equation;

1 mol of Cl2 produces 2 mol of HCl

Converting to mass;

Mass = Number of mol * Molar mass

Cl2;

Mass = 1 mol * 70.906 g/mol = 70.906 g

HCl;

Mass = 2 mol * 36.458 g/mol = 72.916 g

This means;

70.906 g of Cl2 produces 72.916 g of HCl

x g of Cl2 would produce 45g of HCl

70.906 = 72.916

x = 45

x = 45 * 70.906 / 72.916

x = 43.76g

A scientist is comparing 2 samples of the same compound. One is pure and the other is impure. The compound is a solid at room temperature. Explain how the scientist could tell which is the pure compound. [2]

Answers

Answer:

A glass of mineral water is not pure water.

Explanation:

Pure chemical substances

Pouring water into a glass from a bottle

Food and drink may be advertised as ‘pure’. For example, you may see cartons of ‘pure orange juice’ or ‘pure mineral water’. This means that nothing else was added to the orange juice or mineral water during manufacture. However, these substances are not pure to a scientist. In science, a pure substance contains only one element or compound.

Mineral water is mostly water, but there are other substances mixed with it. These are the ingredients that you see listed on the bottle’s label.

dilute hydrochloric acid+zinc metal​

Answers

Explanation:

2HCl+2Zn----> 2ZnCl+H2

Explanation:

HCL + Zn= zncl2 + H2

plz mark my answer as brainlist if you find it useful.

What is the formula for triboron silicide?

Answers

Answer:

B₃Si

Explanation:

Let's take  break it down. From triboron silicide;

Tri - Three

Triboron - Three boron atoms

Silicide - Silicon (with an -ide suffix)

The formular is given as;

B₃Si

what's the correct answer? brainliest​

Answers

Answer:

Explanation:accurate but not precise

The last one is the correct answer

ssignment Vhat challenges would have existed in the spread of Christianity. pe overcome. Remember social media and cell phones did not exis R < previous​

Answers

Answer:

A lot of people rejected it outright. Christians were persecuted and killed for their beliefs, and there were no cars, etc for easy transportation. Most people had to walk everywhere since horses and the like were only for the rich and royal. Hope this helps, please give me brainliest :)

Explanation:

Answer: Your not the best a spelling...

Explanation:

N2 + 3H2 → 2NH3 How many grams of hydrogen are necessary to react completely with 853.42g of nitrogen in the above reaction?

Answers

Answer: 182.87 grams of hydrogen are necessary to react completely with 853.42g of nitrogen.

Explanation:

The balanced chemical reaction is :

[tex]N_2+3H_2\rightarrow 2NH_3[/tex]

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]  

[tex]\text{Number of moles of nitrogen}=\frac{853.42g}{28g/mol}=30.479moles[/tex]

According to stoichiometry:

1 mole of [tex]N_2[/tex] react with = 3 moles of [tex]H_2[/tex]

30.479 moles of [tex]N_2[/tex] will react with=[tex]\frac{3}{1}\times 30.479=91.437moles[/tex] of [tex]H_2[/tex]

 Mass of [tex]H_2[/tex] =[tex]moles\times {\text {Molar mass}}=91.437mol\times 2g/mol=182.87g[/tex]

Thus 182.87 grams of hydrogen are necessary to react completely with 853.42g of nitrogen.

Which process directly moves nutrients from animals to the air?

Answers

D.Breathing

Oxygen obtained through respiration is used by cells in the cellular respiration process to obtain energy. Each animal has a different way of performing gas exchange, but we can say that it is through breathing that all animals move nutrients directly into the air through breathing

I need some help with with question:

How could you prepare 100 ml of a 0.40 mol/L of MgSO4 solution from a stock solution of 2.0 mol/L MgSO4. And then how would u prepare it?

Answers

Answer:

C1V1=C2V2

C1 is 2.0mol/l

V1=?

C2=.4mol/L

V2=100ml or for this 0.1L

V1 is 20ml

Best way to prepare this is to measure out 20ml of the 2 molar solution and add 80mL to it to get to 100mL

Explanation:

please someone help it’s due today(I will give brainliest)

Answers

Answer:

physical or chemical

boiling point

brittleness

opacity

color

density

ductility

shape

hardness

lustre

malleability

melting point

smell

solubility

state of matter

taste

texture

viscosity

Explanation:

the ____metals are in the first column. each of them has full shells, plus one extra electron sitting in a new, outer shell
A) Alkali
B) Alkali Earth
C) Arthropod

Answers

Answer:

The answer is A.

Explanation:

In periodic table, group 1 (1st column) are Alkali metals and group 2 (2nd column) are Alkali Earth metals.

Are physical characteristics of an organism not genetically passed down?

Answers

That is false. Physical characteristics of an organism can be genetically passed down.

—Evidence—

An inherited trait is a feature or characteristic of an organism that has been passed on to it in its genes. This transmission of parental traits to their offspring always follows certain principles or laws. The study of how inherited traits are passed on is called genetics.

In an ecosystem, the  physical characteristics of an organism are genetically passed down  from one generation to another.

What is an ecosystem?

Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.

Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.

Learn more about ecosystem,here:

https://brainly.com/question/13979184

#SPJ2

A) lizard
B) salamander
C) mouse
D) pigeon

Answers

Lizard they are both reptiles
Pretty sure the answer is D. Pigeon

Which of the following statements is the best example of an interaction between the atmosphere and the hydrosphere ? Done rnnnn

Answers

What are the options for the question

A gas has a volume of 500cm3 when a pressure of 100,00N is exacted on it what will be it's volume if the pressure is changed to 150mm mecury at same temperature

Answers

Answer:

See explanation below

Explanation:

At first sight, it seems that the innitial pressure of 100,00 N would be 100,00 N/m² because pressure does not have units of newton alone. If this is true, then the calculations are the following (If it's not, but it's actually mm Hg, then skip the part of the conversion, and just do the procedure of solving for the volume).

The innitial pressure is 100 N/m² or simply 100 Pa. As the second pressure is in mm Hg, let's convert the Pascal units to mm Hg:

1 Pa -----> 0.007501 mm Hg

100 ---------> X

X = 100 * 0.007501 / 1 = 0.7501 mmHg

Now that we have the innitial pressure in mm Hg, and the temperature remains constant, we use the Boyle's law to solve for this:

P₁V₁ = P₂V₂

V₂ = P₁V₁ / P₂  

Using this expression, let's solve for V₂:

V₂ = 0.7501 *¨500 / 150

V₂ = 2.5 cm³

Now, it's the innitial pressure is 100 mm Hg then the volume:

V₂ = 100 * 500 / 150

V₂ = 333.33 cm³

Check the units of the innitial pressure, one of these results should be the correct answer. If it's not, then please post again the question with the correct units.

Hope this helps

how many atoms are in each compound ?

Answers

Compounds are made of two or more atoms of different elements, such as water (H2O) and methane (CH4). Atoms are not drawn to scale. Molecules of compounds have atoms of two or more different elements.

Describe the modern system of classification. Help please!

Answers

Answer:

its called TAXON0MY

Explanation:

they are classified in eight steps namely doma!n, k!ngdom, phylum, class, order, family, genus, and spec!es

but sometimes we do not include doma!n

if you want to name an organism you use both the genus group and the spec!es group

Example:

The scientific name for humans like us is h0m0 sap!ens

H0m0- This is our genus group

sap!ens- This is our spec!es group

sorry for using the exclamation mark it means i

Answer:

The modern system of classification is a hierarchy with eight levels. These levels are domain, kingdom, phylum, class, order, family, genus, and species. There are three domains and six kingdoms in the modern system.

Explanation:

what is the formula for P₃O₅?

Answers

Answer:

i hope its help you

Explanation:

and goodnight,goodevening,goodmorning

First question and I'm already stuck. Help pls!

Answers

Answer:

definite volume. indefinite shape

Answer:

Red

Explanation:

Definite volume, indefinite shape

The transfer of ____________ is achieved when eating and feeding exists

Answers

Answer:

the transfer of energy because eating is gaining energy from a source, so the energy from that source is being transfer to the animal.

The transfer of energy is achieved when eating and feeding exists. Chemical processes may emit or absorb chemical energy.

What is energy?

The ability of a physical process to carry out work is known as energy. It's crucial to remember that simply because energy exists doesn't indicate that it is always ready to do tasks. Thermal energy, sometimes known as heat, is generated when atoms or molecules move. It may be thought of as temperature-related energy.

This energy results from the location of an item. For instance, a ball resting on a table possesses potential energy in relation to the ground because of the influence of gravity. Chemical processes may emit or absorb chemical energy. It is created by atoms and molecules establishing or breaking chemical bonds.

Therefore, the transfer energy is achieved when eating and feeding exists.

To learn more about energy, here:

https://brainly.com/question/29763772

#SPJ2

the speed of sounds depend on

Answers

Answer:

medium in which it is traveling

Explanation:

i hope it helps u

Answer:-
Medium in which the sound waves are travelling.

Explanation:-
To understand this first we need to know that there are 2 types of waves; Mechanical waves and Electromagnetic waves.
Sound waves are mechanical waves meaning they need a medium to propagate. So this clarifies that they will obviously depend on the properties of the medium.
As far as the topic of speed is concerned;
sound travels fastest in solids than through liquids and gases because the molecules of a solid are closer together and, therefore, can transmit the vibrations (energy) faster.
Link:-
https://youtu.be/yF4cvbAYjwI

Hope it helps, feel free to clarify any confusion/confusions.

Chlorine reacts very violently. What about its electron shells makes this the case?

Answers

Answer:

it readily gains another electron. the outer electron shell is closer to the nucleus, than iodine for example, which makes it less shielded (greater attraction for another electron = violent reaction to get it)

Explanation:

Elements and compounds are usually more dense in their solid than in their
liquid state. However, water is one of the notable exceptions. The density
of ice is 0.917 g/mL, while the density of liquid water is 1.00 g/mL. What
natural phenomena does this explain?

Answers

Explanation:

The molecules in water is more tightly packed than in ice, so water has greater density than ice.

What is the volume of 104 g of ethine under normal conditions?​

Answers

0.143 moles is the volume of 104 g of ethine under normal conditions

What properties do atoms of the same element share? Select all that apply
atomic number
chemical reactivity
melting point

Answers

Answer: your answer is A

Explanation: the atoms has the same properties of the same element as the atomic number.

What are some genaral properties of gases that govern their behavior

Answers

Answer:

1. Gases may be compressed

2. Gases expand when less pressure is applied.

3. Gases can be mixed.

4. Gases exert a constant pressure on its container walls.

5. Gases have low densities.

Glass or anything that is breaking

Which of these is incorrect

Answers

Answer:

B

Explanation:

Ne has 10 electrons.

so the first shell will takes 2 (10-2=8)

the second shell will take 8 (8-8=0)

b would be wrong
bet

Metal x combines with fluorine to form XF2. what compound does it form with the sulfate ion?
A. XSO4
B. X2SO4
C.X(SO4)2

Answers

Explanation:

The answer is A b/c

the polyatomic SO4² have 2 valance electron,also

the metal X also have 2 valance electron so,They cancel each other

A because it’s times the metal divided by the copper

Una sola dosis de etanol, C2 H5 OH, eleva el nivel intracelular de iones calcio. Los iones Ca2+ liberados por el etanol 0,10 M matan las células del hígado de las ratas. Expresa esta concentración en gramos por litro. ¿Cuál es el porcentaje en volumen? (La densidad del etanol es de 0,785 g/mL.)

Answers

Answer:

No se bro cual se la respuesta .......

Explanation:

lo siento(

Other Questions
There are 16 ounces in 1 pound, so the expression z/16, where z represents the number of ounces, can be used to find the number of pounds for any given number of ounces. How many pounds are in 40 ounces? 18. Using the video, build the protein using the given DNA sequence. What is the final amino acid sequence?Important: Be sure to write each correct amino acid before clicking, as it will disappear! PLEASE I NEED HELP PLS THANK U SM MATH vi. The value of a machine depreciates 20% annually. If its present value is Rs. 20,000, its valueafter 2 years will bestep-by-step What type of organisms receive energy from all other organisms? What are the types of graphs for Class 7? 1Write the place value of the underlined digit in each number. The place values arespelled correctly for you here:hundredstensonestenthshundredths During the 1970s, which piece legislation did national organization for women actively, though it was never ratified Who were the members of the "Lost Generation"?A. U.S. citizens that left the United States to livein other countriesB. disillusioned American writers that soughtnew forms of expressionc. political radicals that opposed the U.S.governmentD. farmers that moved to the city after defaultingon their farms Find the slope of a line perpendicular to the line whose equation is x - 2y = 14.Fully simplify your answer. What are the five reasons why we study? Evaluate The Following Integral If R [0, 1] X [0, 1]. 3yexy DA A geometric sequence begins with 4, 20, 100, 405, Which option below represents the formula for the sequence? f(n) = 5(4)n1 f(n) = 4(5)n1 f(n) = 5(4)n f(n) = 4(5)n 1/216 as a power of 6 A depth finder shows that the water in a certain place is 620 feet deep.The difference between d,the actual depth of the water, and the reading is |d-620] and must be less than or equal to 0.05d. Find the minimum and maximum values of d, to the nearest tenth of a foot. jonah is playing a game with his frind rita.there using a spiner below for there game.If jonah spins the spinner twice ,which of these reprensents the possible outcomes of his spin Duval company issues four-year bonds with a $100,000 par value on january 1, 2021, at a price of $95,952. The annual contract rate is 7%, and interest is paid semiannually on june 30 and december 31. BEST ANSWER WILL GET MARKED BRAINIEST!I am inviting 32 people for my sweet sixteen. Is that considered as a lot of people? How might the term revolution be viewed as an oxymoron? How do i solve 6/8 divided by 9/8?