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Finite math, K201, calculus, and statistics explained

Today, we're releasing the first of our K201 Excel series videos.

In this how-to video, Dalia explains date functions, including today, yesterday, future dates, and date differences (datedif). While easy to understand, these concepts are also easily forgettable. We recommend brushing up on these functions once or twice before an exam.

Download the exercise files

Stay tuned, we'll be posting new videos every week for the rest of the semester. If you need additional help, reach out to us via our tutoring request page! We'd be happy to help.

Dalia strikes again with this handy reference guide for the Microsoft Access portion of K201 at IU Bloomington. This is not intended as a complete introduction to using Access. It assumes that you have the basics down, and tries to cover the specific topics where K201 students tend to get stuck the most often.

Dates

Quarters

Quarter Months Expression
Quarter 1 January, February, March Between #1/1/2016# and #3/31/2016#
Quarter 2 April, May, June Between #4/1/2016# and #6/30/2016#
Quarter 3 July, August, September Between #7/1/2016# and #9/30/2016#
Quarter 4 October, November, December Between #10/1/2016# and #12/31/2016#

Other Date Functions

Date Expression
Today's date Date()
Yesterday Date()-1
Tomorrow Date()+1
3 months from now Date()+90

How many days are in a month?

I do the knuckle trick!

Totals Row

Whenever you see multiple rows of potentially the same data you need to turn on your totals row.

Turn unnecessa...

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Today's post is courtesy of our awesome K201 tutor Dalia, who wants you to get comfortable with some of Excel's more common lookup and indexing functions. This is one of the hardest parts of Excel for most people, and where students tend to get stuck in the class.

One of the more powerful features of Excel is the ability to automatically cross-reference a table of values based on some input value(s). For example, you might have a spreadsheet that computes your company's total revenue from each customer, but to do that it must look up the hourly rate and total number of billed hours for each customer from another spreadsheet. When used like this, spreadsheets can almost (but not quite) be used like the relational databases you studied in the first half of K201.

The most common functions you'll use for cross-referencing in Excel are:

  • VLOOKUP and HLOOKUP
  • MATCH
  • INDEX

Both VLOOKUP and HLOOKUPs are used in the same way, so from now on we'll just refer to them collectiv...

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After the finite midterm, you may have been confused and annoyed when the class seemed to abruptly shift from probabilities and permutations to matrices and systems of equations. They seem to have nothing to do with each other!

Well, today is your lucky day. Probability theory and matrices have finally met, fallen in love, and had a beautiful baby named Markov.

Let me explain. Markov processes are widely used in economics, chemistry, biology and just about every other field to model systems that can be in one or more states with certain probabilities. These probabilities change over time.

For example, we might want model the probability of whether or not Amazon.com turns a profit each quarter. So, Amazon.com (the system) can be in two possible states at the end of each quarter: either they turn a profit, or they don't. Their chance of turning a profit this quarter depends on whether or not they turned a profit last quarter. For example, if they profited last quarte...

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Today, let's take a look at everyone's favorite matrix application problem, Leontief input-output models. You might know them simply as "technology matrix" problems, but actually the technology matrix is only one part of the problem. The really interesting part is in the derivation of the matrix equation - something that most finite math courses seem to gloss over in the end-of-semester frenzy.

So, let's take a look at a typical "technology matrix" problem, and see if we can't understand how the problem actually works. Hopefully, it will make it easier to remember than an arbitrary formula.

Example: An economy consists of two codependent industries - steel and lumber. It takes 0.1 units of steel and 0.5 units of lumber to make each unit of steel. It takes 0.2 units of steel and 0.0 units of lumber to make each unit of lumber. The economy will export 16 units of steel and 8 units of lumber next month. How many units of steel and lumber will they need to product...

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