## How to analyze whether X, Y affect Z over time.

I have a data-set, and the details are not crucial, but if it helps: The variables are (A) country, (B) investment, (C) campaign type, (D) external event. Obviously A is a categorical variable, B is a continuous quantitative variable, C is categorical, and D is a Bernoulli variable. I also have information about these for each year stretching back decades. I would like to know whether A, C, and D cause changes in B and exactly what that causal relationship is if it exists.

So my question is, how should I analyze this data, in broad terms? Should I use Time Series Analysis? It sounds like this should be a time-series problem but given that I’ve never studied the subject, I’m not certain. Is it possible to derive causal information from this data given that it’s observational? It would be particularly great if there were some textbook or other resource that I could read to learn about the tools I ought to be using in a case like this.

## How to get gasoline out of your diesel engine.

Let my roommate and his friends borrow my car for a fourth of July parade. Told them it only took diesel, just in case they needed to fill it up. Then the dumbasses put gasoline in there. They called me saying that the car won’t start. I’m on my way there, but have no idea how to fix this massive fuckup.

submitted by /u/wsdpii

## In Gratitude of America’s Automotive Freedom

In an age where cars are increasingly constrained by environmental regulations, safety mandates and distracted drivers, we still have it good in America. After driving across the country multiple times, I’m in awe of the thousands of miles of interstate highway that connect every city and state. We still have lower fuel prices than most Western countries, and American consumers have a huge range of new and used vehicles to choose from. Car manufacturers are constantly innovating for better safety and fuel economy; and we still get some really cool designs like the Raptor and Challenger Hellcat. Car culture is alive and well, with vibrant communities for every automotive niche. And whatever you think of Tesla – they are still the best know manufacturer of EVs, and they are pushing the needle on some really interesting technologies.

On this Independence Day, I find myself grateful that America is home to a sort of Utopia for gearheads.

submitted by /u/Toast-haste

## Getting the squareroot of n using a semicircle with diameter n+1

I came across this Numberphile video (because it was linked in a recent Objectivity video with the same title) and in it, a method for getting the squareroot was presented.

A part of my brain tells me this isn’t true, and I couldn’t seem to find a proof of this online. And I couldn’t think of my own one either. I tried using proof by induction, and it seems to work on the base case n=1. That is, the diameter is 1+1, the radius is 1, and since the perpendicular line from the end of n to the semicircle is of length 1 (in this case, the radius) and the squareroot is 1, it holds true for the base case. But since its been ages since i last had a geometry related course (i took up computer science), I couldnt move on to prove the inductive step. Can anyone help me find a proof for it?

submitted by /u/d10p3t

## A question about Gödel’s incompleteness

It seems to me that all Gödel proposes is a statement that “says”: this statement is not in the set of all statements that can be proved. And from that arises either a contradiction or the conclusion that the set of axioms are incomplete. My question is, and don’t take this the wrong way, Is Gödel’s merit basically putting all this in a systematic way with Gödel’s encoding? Because it doesn’t seem too complex compared to contemporary mathematics.

submitted by /u/jjjjjj1317

## My Project E46 M3 Is Nearly Complete!

Remember the Marrakesh Brown M3 I posted over half a year ago?

Well here she is today after a very thorough detail:

https://www.instagram.com/p/Bk0DRLNHe3N/

Shes come a long way since September last year:

https://www.instagram.com/p/BYp0Jd4Dfff/

(I hope the mods are ok with me linking to Instagram)

I have literally changed everything on this 2001 M3, its as close to new as can be other than the fact the engine has done over 130,000 miles. The S54 is an incredibly strong engine, as long as you keep on top of maintenance and feed it shit tons of money, I can’t see why it wouldn’t do another 130,000 miles. 😉

All that’s left to do now is install the roll cage, drive shafts, ABS sensors, tidy up some interior bits and tune the car for that lovely CSL air box.

She will be at the Goodwood Festival Of Speed in the Performance Parking area on Thursday, so feel free to say hi.

I thought this would be of interest to some of you, or perhaps inspire some to keep at their project cars. Often you see a project start on a forum and it eventually just disappears unfinished as we give up when costs spiral out of control or something else happens.

I would be lying if I told you this was easy. So many terrible events have occurred in my personal life that at least half a dozen times I considered just walking away. But in the end I persevered, doubled my original budget and now plan to keep this car forever (makes no financial sense to sell and its an awesome experience to drive!)

Later this month I will list all the parts that were replaced….. and also disclose how much I spent! :s

submitted by /u/The-Benchmark

## Recently started my first blog website (no ads or selling anything) about hookahs.

I love hookah, and I decided to start a blog talking about it. It has information on anything related to hookah. I thought I’d post it here to get any feedback. Here’s the link to it: http://www.hookah-daily.info/ submitted by /u/hookah_lover [link] [comments]

## Help understanding the statistical effects of sample reduction in a study?

Hey everyone, so I’m having issues figuring out exactly what I’m looking for in a study here .

Specifically, –what is the percentage chance that the all-cause-mortality numbers for vegan men and vegan women are caused by increased variance from sample size reduction?

Put another way, how much of the variance can be explained by the effect of splitting the sample into men & women vs some other factor?

From what I can gather, n for vegan men = 2015, and 3533 for women here

With the .95 CI for the base mortality of all vegans being .85 (.73-1.01) here

The .95 confidence interval for women is .97 (.78-1.20) here

and for men it is .72 (.56-.92) here

I thought maybe this would be some type of ANOVA situation, but I’m not sure. I hope my question makes sense, let me know if I need to explain further.

submitted by /u/Jdriii