Category Archives: STEM: Sci, Tech, Engineering, Math

What makes a good business? Part 3 of the IRR trilogy

This post was inspired by reading a Quora response where the child of a top 1% family says that one of the advantages of his upbringing is that his parents taught him about how business works. “Business” is a somewhat broad term that some schools say takes two years and $120k in tuition to “master”. However, as we typically do in this blog, we can educate ourselves on some of the central concepts of business on our own through spreadsheets!

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Our hope is that anyone with internet access can find this page and play around with the spreadsheets to begin to think about what makes a good business. Now if only this site could also provide the exotic travel experiences, connections, and the ability to take risks with a safety net that growing up in the 1% also provides… Continue reading

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Is medical school “worth it”? An introduction to Internal Rate of Return (“IRR”)

Finance hiring is down, law school grads are having a tough time finding real law jobs, so what is an ambitious but risk averse college student to do with his or her life these days? Okay, right now the answer is computer science. Yes seriously, do computer science. But let’s pretend it is the year 2001 and the only other option respectable option is medical school. But doesn’t med school take a lot of time (4 years school plus 3-7 years residency/fellowship) and cost a lot of money? How can we figure out if going to med school and not earning doctor money until 7 years from now is worth it financially relative to just entering the workforce and working for those 7 years? Continue reading

Build a Spreadsheet to help you choose a healthcare plan

Will you save more with standard PPO or a high-deductible PPO Saver plan with a Health Savings Account?

It is currently Open Enrollment season at many workplaces, which is when employees choose their medical insurance and other benefits plans for the upcoming year. It’s also the time of year when people grumble “why is the US healthcare system so complicated” and just elect whatever plan they had in the prior year. Building a spreadsheet can help someone compare the costs and benefits of each of the plans under a variety of different assumptions about tax rate and healthcare expenditure. Continue reading

Do you want the stock market to go up or down?

At first glance, it sounds like an obvious question – surely it is better when stocks go up, right? From watching the ads on CNBC, it would seem that higher stock prices directly translate into more steak dinners and golf vacations while lower stock prices mean bringing your own peanut butter sandwiches to work (jelly is for bull markets). Continue reading

Bayes’ Rule, Oscars, & Golden Globes

TechsmithWor50C6.pngHave you heard of Bayes’ Rule? Let’s use an intuitive example to understand an application of this rule. What’s the probability American Hustle wins the Golden Globes given it wins the Oscars? Continue reading

Improve Agreement Accuracy with Kappa

TechsmithWor2DE0.pngHave you heard of kappa, a measure of inter-rater agreement? In this post, we’ll delve into this statistic and see how spreadsheets can help us calculate and understand it.  Continue reading

What’s the Volume of a Pyramid?

TechsmithWor7C5E.pngHow many cubic feet of sand can a pyramid hold? Did you know that it is exactly 1/3 of the volume of a rectangular prism with the same height, base, and width as the pyramid? Let’s use spreadsheets to confirm this and calculate the volume of other geometric solids.

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Predicting a Tennis Pro’s Weight based on Height

TechsmithWorEE2E.pngWith a Grand Slam approaching, let’s talk tennis! If we were to predict a tennis pro’s weight based on his height, where would we begin? How will our understanding of the best-fit line and spreadsheets help us make this prediction?

We’ve collected the heights and weights of tennis pros including Federer, Djokovic, Nadal, Murray, Azarenka, Sharapova, and Williams, along with another 192 top players. Let’s investigate how to 1) calculate the correlation of weights and heights, and 2) draw a best fit-line and scatter plot in Google spreadsheets to extrapolate or make predictions!

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Calculate Distance Traveled with Spreadsheets

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Photo: Katie Ko

If you have data such as velocity and time traveled, would you be able to calculate the total distance journeyed? Let’s discover how to tackle this question with spreadsheets! We’ll first begin by calculating distance traveled when velocity is constant. Then we’ll approach a more realistic situation of varying velocity using the Mid Rectangular Approximation Method (MRAM)! Continue reading

Take the ‘Order of Operations’ Spreadsheet Quiz!

TechsmithWor63E8.pngKnow the rules of the order of operations? A central concept in pre-algebra/algebra, these rules clarify which actions in any algebraic expression should be performed first. Let’s review what the rules are and why they are important. Then, you can test your knowledge with a spreadsheet quiz!   Continue reading

How Accurate is your Robot? Measurement Error & Spreadsheets

No robot or machinery is consistently perfect. Glitches might occur with overuse, or the environment is unsuitable. While achieving a perfectly functioning robot is a noteworthy goal, it may not be realistic. So, what level of error or tolerance level would you be willing to accept? Let’s discover how to use spreadsheets as a tool for understanding and calculating measurement error. Continue reading

Probabilities & Dice Roll Simulations in Spreadsheets

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Photo: Amie Chuang

What is the probability of rolling any pair of numbers with two dice? Let’s first solve this and then confirm our calculated probability by simulating 500 dice rolls with a spreadsheet! In this post, we will focus on understanding basic probability concepts and then discover how with spreadsheets, we can actually see whether our calculated probability holds true!

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