Data and Spreadsheet

Data and Spreadsheets 4 What are data? 4 What are statistics? 4 What are spreadsheets? 4 How can you analyze data with spreadsheets?

Data 4 Data are pieces of information that can define subjects 4 Data can be numbers, words, descriptions 4 The word data is PLURAL, datum is singular 4 Example of Data about George: Age: 57.2 (years) 43rd President Male Favorite letter: W Favorite words: Bring them on.

Types of Data 4 Numbers – two types –Real #s – rational numbers – 57 years –Integers – whole numbers – 170 lbs 4 Letters – called characters in programming –W is a character 4 Words – called strings in programming –“Bring them on” is a strings, can be individual words or phrases 4 Other : Image, Sound…

Statistics and Data 4 Test Scores: –Jeff: 88 –Mollie: 92 –Marcie: 88 –Dave: 47 –Karim: 99 –Willoughby: 6 –Benjamin: 0 4 What statistics can you calculate to describe these data? –Try to think of four things to describe the data 4 stop

Statistics 4 Statistics are derived from the data 4 Statistics are descriptions of data 4 Statistics are meant to simplify the data 4 Statistics can be misleading

Typical Statistics 4 Sample Size - number of individuals measured = n  Sum =   Average or Mean =  /n 4 Median –Value of 50th percentile, half of values fall above, half below 4 Maximum, Minimum, Range (Max-Min) 4 Mode - most common value 4 Standard deviation 4 Variance (SD 2 )

Analyze these data... 4 Mean, max, min, range, median, mode sample size (n) 4 Mode  Sum   mean=average=  /n 4 median = halfway  Variance =  (x-mean) 2 /n

Calculators Compared with Spreadsheets CalculatorsSpreadsheets Single CalculationMany Interrelated Calculations at Once Built-in Math Operators Built-in and customized Math Operation Complex Calculations: One Step at a Time Change a Value: Repeat the Calculations you Defined

Spreadsheets 4 Spreadsheets are tables 4 Spreadsheets allow calculations and manipulations of data Calculations: mean, standard deviation Manipulations: sort, Visualizations: plot, pie chart

Spreadsheet Design Questions 4 What numbers are you starting with? 4 What numbers do you need to calculate? 4 What are the relationships among the numbers to perform these calculations? 4 What text do you need to make the spreadsheet clear to yourself and other people?

Make a data table: 4 Fly 1, length 13.4 mm, velocity 27 Kph, age 21 days 4 Fly 2, length 9.4 mm, velocity 0 Kph, age 220 days 4 Fly 3, length 9.3 mm, velocity 44 Kph, age 1 days 4 Fly 4, length 13.4 mm, velocity 17 Kph, age 32 days 4 Fly 5, length 17.4 mm, velocity 33 Kph, age 11 days 4 How many columns? 4 How many rows? 4 #s go down or across?

Data Table Fly #LengthVelocityAge

Microsoft Excel 4 Typical spreadsheet program –VisiCalc is original commercial spreadsheet –Lotus took over in the 1980s. 4 Has similar controls to MS Word 4 Now allows graphing (charts) 4 Excel tables and graphs can be copied into MS Word

Excel Basic 4 Data are stored in cells. 4 Cells are name by Letters and numbers e.g. A12. This is also called cell reference. 4 Cells can hold number, text, image, and most important thing: Formula. 4 Formulas are started with a “=” sign. It can be any mathematical operations.

Relative Cell Reference

Absolute Cell reference

Friday’s Assignment 4 We will work with Microsoft Excel to analyze some data 4 Groups of two will submit one finished spreadsheet for the assignment