:)

A population of values has a normal distribution with a mean of 215.1 and a standard deviation of 45.7. You draw random samples of size n=57. What is the value separating the bottom 72% of means from the top 28% of means in your sampling distribution? Round your answer to 1 decimal place.

I'm not sure how to figure out this problem. Can someone write out the steps and explain how to do it, so it makes ore sense?

Thanks!

I'm writing a history paper and I'm having trouble finding facts to back up how unfairly Germany was treated.

As a solution of KBr and water boils, only the water molecules will vaporize. What should happen to the boiling point temperature over time as such a solution boils?

what's the process?

My mom's birthday is coming up and I want to do something really nice for her. I always get her a gift and a card, but I want to do something really unique or different than normal this year. Does anyone have any good ideas?

Thanks!(:

My homework asks me to write the equation for the reaction that would occur between aqueous chloride ion and aqueous bromine if bromine is a stronger oxidizing agent than chlorine.

It also asks to write the equation for the reaction that would occur between aqueous bromide ion and aqueous chlorine if chlorine is a stronger oxidizing agent than bromine.

Can both of the reactions be favorable under the same conditions?

Does anyone know how to do these? Can you explain why the reaction is what it is to me?

Thank you so much for the help!(:

My homework asks me to find the energy required to make the transition from n=1 to n=infinity. I've tried this problem over and over and I keep getting the wrong answer! I would love if someone could walk me through it step by step! Thanks for the help!

I have a gummy smile and I really want to get it fixed. I was wondering if anyone had had this done before? Did you have a good experience with it? And about how much did it cost you?

Thanks!

Here's the reaction:

2Mg(s)+O2(g)---->2MgO(s)

enthalpy (delta H)= -1204KJ

calculate the amount of heat transferred when 2.5g or Mg(s) reacts at constant pressure.

I have no idea where to even start with this problem! I would love if someone could explain to me how to find the answer to this!

Thanks for the help!

A gas is confined to a cylinder under constant atmospheric pressure. When 418 J of heat is added to the gas, it expands and does 105 J of work on the surroundings.

please explain.

I know the equation Change in enthalpy=change in energy + pressure(change in volume)

change in energy=heat + work

I tried putting the numbers into the equation, but I didn't get the right answer!

Thanks for the help!

Please explain

I know the ideal gas equation: PV=nRT

I don't know the number of moles or the pressure of the gas, so I can't solve for one variable.

I can't convert grams to moles, because I don't know which gas it is, so I don't know the molar mass of it.

Does anyone know another equation or a way I can find the pressure of this gas??

-Thanks for the help!(:

thanks for the help!

I added 25mL of H2C2O4 to a substance and I'm supposed to find the number of moles I added!

I know density is part of this equation and its mass/volume. Would I just put the molecular weght of H2C2O4 over 25.0mL?

any help is appreciated!

Thanks!

where would I find a historians opinion on a topic?

I'm looking for someone's opinion on whether or not the puritans should have treated the native americans better. But I have no idea where to find this!

Thanks for all the help!

I have to answer the question: should the puritans have treated the native americans better?

I have to have some historian's responses and some good facts. I'm having trouble finding resources online for this though. If I type it in on google, all that come up are essays that have already been written by students. Does anyone know where I can find some historian opinions on this?

Links would be extremely helpful!

Thanks so much!

HNCO ----> C3N3(NH2)3 + CO2

thanks for the help(:

Hydrogen cyanide, HCN, is a poisonous gas. The lethal dose is approximately 300 mg HCN per kilogram of air when inhaled. The density of air at 26 degrees celsius is 0.00118 g/cm^3

.Calculate the amount of HCN that gives the lethal dose in a small laboratory room measuring 12.0 X 15.0 X 9.40ft

I dont even know to stare with this. I would love if someone could explain it to me step by step!

Thanks for the help!(:

C5H6O + O2------> CO2 + H2O

Hydrogen cyanide, , is a poisonous gas. The lethal dose is approximately 300. per kilogram of air when inhaled. The density of air at 26 is 0.00118 .

Calculate the amount of that gives the lethal dose in a small laboratory room measuring .

I have no idea where to even start with this problem! I would love if someone could explain it to me step by step!

Thanks for the help!(: