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Data and Spreadsheet. Data and Spreadsheets. What are data? What are statistics? What are spreadsheets? How can you analyze data with spreadsheets?. Data. Data are pieces of information that can define subjects Data can be numbers, words, descriptions
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Data and Spreadsheets • What are data? • What are statistics? • What are spreadsheets? • How can you analyze data with spreadsheets?
Data • Data are pieces of information that can define subjects • Data can be numbers, words, descriptions • The word data is PLURAL, datum is singular • Example of Data about George: • Age: 57.2 (years) • 43rd President • Male • Favorite letter: W • Favorite words: Bring them on.
Types of Data • Numbers – two types • Real #s – rational numbers – 57 years • Integers – whole numbers – 170 lbs • Letters – called characters in programming • W is a character • Words – called strings in programming • “Bring them on” is a strings, can be individual words or phrases • Other : Image, Sound…
Test Scores: Jeff: 88 Mollie: 92 Marcie: 88 Dave: 47 Karim: 99 Willoughby: 6 Benjamin: 0 What statistics can you calculate to describe these data? Try to think of four things to describe the data stop Statistics and Data
Statistics • Statistics are derived from the data • Statistics are descriptions of data • Statistics are meant to simplify the data • Statistics can be misleading
Typical Statistics • Sample Size - number of individuals measured = n • Sum = S • Average or Mean = S/n • Median • Value of 50th percentile, half of values fall above, half below • Maximum, Minimum, Range (Max-Min) • Mode - most common value • Standard deviation • Variance (SD2)
Mean, max, min, range, median, mode 18 33 4 47 49 38 29 4 55 sample size (n) Mode Sum S mean=average=S/n median = halfway Variance =S(x-mean)2/n Analyze these data...
Spreadsheets • Spreadsheets are tables • Spreadsheets allow calculations and manipulations of data • Calculations: mean, standard deviation • Manipulations: sort, • Visualizations: plot, pie chart
Spreadsheet Design Questions • What numbers are you starting with? • What numbers do you need to calculate? • What are the relationships among the numbers to perform these calculations? • What text do you need to make the spreadsheet clear to yourself and other people?
Make a data table: • Fly 1, length 13.4 mm, velocity 27 Kph, age 21 days • Fly 2, length 9.4 mm, velocity 0 Kph, age 220 days • Fly 3, length 9.3 mm, velocity 44 Kph, age 1 days • Fly 4, length 13.4 mm, velocity 17 Kph, age 32 days • Fly 5, length 17.4 mm, velocity 33 Kph, age 11 days • How many columns? • How many rows? • #s go down or across?
Microsoft Excel • Typical spreadsheet program • VisiCalc is original commercial spreadsheet • Lotus 1-2-3 took over in the 1980s. • Has similar controls to MS Word • Now allows graphing (charts) • Excel tables and graphs can be copied into MS Word
Excel Basic • Data are stored in cells. • Cells are name by Letters and numbers e.g. A12. This is also called cell reference. • Cells can hold number, text, image, and most important thing: Formula. • Formulas are started with a “=” sign. It can be any mathematical operations.
Friday’s Assignment • We will work with Microsoft Excel to analyze some data • Groups of two will submit one finished spreadsheet for the assignment