Data and Spreadsheet
Data and Spreadsheets
What are data?
What are statistics?
What are spreadsheets?
How can you analyze data with
Data are pieces of information that can define
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
• 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
Other : Image, Sound…
Statistics and Data
Test Scores: What statistics can you
– Jeff: 88 calculate to describe
– Mollie: 92 these data?
– Marcie: 88
– Dave: 47 – Try to think of four
– Karim: 99 things to describe the
– Willoughby: 6 data
– Benjamin: 0 stop
Statistics are derived from the data
Statistics are descriptions of data
Statistics are meant to simplify the data
Statistics can be misleading
Sample Size - number of individuals measured = n
Sum = S
Average or Mean = S/n
– Value of 50th percentile, half of values fall above, half below
Maximum, Minimum, Range (Max-Min)
Mode - most common value
Variance (SD )
Analyze these data...
Mean, max, min, sample size (n)
range, median, mode Mode
• 38 median = halfway
• 29 Variance =S(x-mean)2/n
Calculators Compared with
Single Calculation Many Interrelated
Calculations at Once
Built-in Math Built-in and customized
Operators Math Operation
Complex Calculations: Change a Value: Repeat
One Step at a Time the Calculations you
Spreadsheets are tables
Rainforest 625,000 3,712,000
Dry Forest 50,000 300,000
Total 675,000 4,012,000
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
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?
Fly # Length Velocity Age
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
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.
Relative Cell Reference
Absolute Cell reference
We will work with Microsoft Excel to
analyze some data
Groups of two will submit one finished
spreadsheet for the assignment