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Lecture 5: Data Analysis for Modeling

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Data Analysis in the Context of Modeling

• Supports the modeling process– Improves accuracy of model– Improves usefulness of conclusions

• Modeling is the primary goal.– Data analysis is a means to that goal.

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Topics for Chapter

• Finding facts in databases– Editing, – Searching, – Sorting, – Filtering, and – Tabulating

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Finding Facts from Databases

• Tables of information• Each row is a record in the database.• Each column is a field for the records.• Excel calls such a table a list.

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Excel Lists

• First row contains names for each field• Each successive row contains one record.• Lists may be:– Searched and edited– Sorted– Filtered– Tabulated

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Searching and Editing Lists

• First assign a range name to entire list.– Include column titles.

• With list selected Form on the Quick Access Toolbar.

• Examine records one at a time:– Find Prev.– Find Next.– Enter new record with New button.– Delete record with Delete button.

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Database Form

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Criteria Button

• Selected Form on the Quick Access Toolbar • Allows for searching of records– Enter data into a field. – Click Find Next.

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Alternate Excel Search Techniques

• Highlight entire database. • Home"Editing Find&Select Find.► ►• Use Find and Replace to edit entries.• In Find and Replace– “?” stands for any single symbol– “*” stands for any sequence of symbols

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Sorting: Data – Sort Command

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Filtering

Choose Home Editing Sort&Filter Filter.► ► ►Will filter lists based on values

Found under arrow at the title of each columnArrow on title turns blue to remind list is filteredCan remove filter by:

Choose Home Editing Sort & Filter Filter Clear► ► ► ►

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More Filtering

• Top 10 option returns records with smallest or largest value of a numerical record

• Custom option allows filtering with compound criteria

• More complicated compound criteria can be achieved by clicking Custom Filter option under Number Filters or Text Filters.

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Tabulating

• Select Data – Pivot Table.• Creates summary tables• Layout button on

third step of wizard creates the format for the table

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