Are these correct?

Recently had a quiz and got an item wrong. Item gave 2 samples of size n = 10, and a question asked to test that Method/sample B (mean is 77, Sd = 5.395471) is better than Method/sample A (mean = 73, Sd = 3.366502) over a 90% confidence interval.

I assumed this would be a two-sample t-test for estimating difference of means or something, relating to if method B on average performed better, but apparently that was wrong, and the answer sheet provided as we finished showed the use of an F-distribution, suggesting to compare the variances of each sample.

1. is my interpretation wrong? was I supposed to interpret "better" as lower variability rather than which sample scored higher on average?

2. my professor got an interval of (0.1224, 1.238), but I only achieved this result by computing 3.366502² / 5.395471², but I was under the assumption that you generally put the larger variance on top, which gave me different values. Is this perhaps a specific case different from the correct case for solving this item? Other items calling for an F-test were one-tailed hypothesis testing,and for those items, assuming the larger variance on top was correct apparently. Should I have assumed to use the natural order sA/sB since this is a two-tail problem? or is it something else?

Apologies if muh incompetent and ignoramus, this really isn't my strongsuit. Appreciate any help!

(I can't really ask my professor now, because it's currently basically dawn where I live)

Sorry I'm so confused they said they wanted horizontal speed why are they using conservation of energy

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I attached the work I did for the first 2 questions

It’s about relicts I genuinely can’t find enough information on them for the questions I need to answer. The questions are: The definition of relicts, what type of animal and plant relicts are there, locations of some relicts, relict properties as to what makes them classified as a relict and notes about them.

I

Our teacher never actually explains why she does things just how (because she sucks) and now idk what I've done wrong.

I'm reviewing my homework and trying to practice learning the questions. I found most answers with showing the work which is what I need. In this problem they show getting the ratios of 12/25, 8/25, and 5/25. What they don't show is how they got those ratios and it's what I'm struggling with understanding the most in this class. I'd like it if someone could show me how they are getting these ratios so I can write it in my notes.

i hate circles

For Q32, My friends say 1v while chatGPT says 3v, and I personally am not sure where do I start from. Some hints or insights would be appreciated!

and i know in a cascading op-amp netowork the output of op-amp is the input of another, but the other omp amp might or might not be in saturation correct? depending on the feedback resitors etc.

guyss i need help with a qu. so i have to prepare master budget from a qu but my balance sheet isn’t not matching which means that i missed something out. can someone please help me out with the cash budget and budgeted balance sheet please😭😭 i’ve been stuck on it for hours

guyss i need help with a qu. so i have to prepare master budget from a qu but my balance sheet isn’t not matching which means that i missed something out. can someone please help me out with the cash budget and budgeted balance sheet please😭😭 i’ve been stuck on it for hours

Can someone explain how Efron's Biased Coin Design works in practice and how it might be carried out? I think I get the basic idea, but when I look it up the language used to explain BCD is a little confusing.

My knowledge of statistics is pretty basic. I came across this term while doing research for my educational assessment course and I would like to understand it better.

Thanks!

Hi how would I find the boundary y(m)?

I worked out maybe I could use the area of a trapezoid equation a=.5(b+b1)h however when I do this I have too many unknowns as I don’t have the area ?

What is another method to solve this ?

For context, this was done online. The problem is that the graph can't be made as the vertex/maximum point can't be placed on (2, 45) as the graph only lets you place points in increments of 10. The automatic hint also says I need to put it on (2, 45) even though it won't work.

1: Is there a simple rule of thumb for which unit conversion of Planck's constant, joule or electronvolt, to use in physics calculations? This is often easy to deduce, but not always at least in my book's exercises.

2: Why doesn't the total number of neutrons and protons, or the number of nucleons A, in the answers to the book's exercises often follow the table book I have?

The answers seem to follow the given Z number, or the number of protons, but the given A number is often not found at all under this Z number. In other words, in the book's exercises, an element is often given an isotope that doesn't exist. Or if it does exist (this is more likely), it is not listed in the table book. The example exercise deals with the 238Pu isotope. I look at the table book and they jump straight from 237Pu to 239Pu. What's the point? I would understand if there were, for example, so many isotopes that it wouldn't make sense to list them. This just doesn't seem to follow any clear logic. Sometimes they are missing, sometimes not.

I have no idea how to write 2-bromoethyl salicylate. I know how to write salicylate but I'm not sure how the bromoethyl fits into it. Can someone please help?

I'm working on a mechanics problem related to moments and need some help understanding the solution.

I’m unsure how to approach it. Could someone explain the steps to solve it? Any help would be greatly appreciated!

second part just did sin inverse of 2 and got invalid got no clue what to do.

ive been trying this for hours i tried doing assumoption n=k then RTP for n=k+1 then subbing the assumption into the LHS of the RTP then combining the fractions then using double angle but I can't simplify from there to get LHS of RTP could somene please show me on paper or ipad how to do the algebra for this question.

Hi,

I started a Geography Club at my school, and we’re working on Scan the World, a huge flag display with slides about different countries. Me and my friends have already put in over 15 hours, and we’re still not even halfway done. It’s way more work than we expected, and we really need help!

I made a copy of the slides so anyone online can pitch in. If you can spare some time, please check out the link—it would mean the world to us. Thanks so much! ( We need to finish by then end of April)

https://docs.google.com/presentation/d/1Tx1fJXgrMz5nNXOc0WbuxT91dKFCczxjzucaCtbmXtc/edit#slide=id.g33dae9ec0a1_0_0 (For instructions just follow the example on the slide)

Hi, currently studying for my exam next week and this question has stumped me. I know the mass for calcium is 40.07g, but I have no idea how to begin calculating the atoms with this given number of 12.04 x 10^23 other than dividing by Avogadro's number (Unless that's wrong too.). The correct answer is 6.020 x 10^23 atoms, but I genuinely don't know how to get that. I would really appreciate it if anyone could help me, thanks in advance for anyone who does!