Practice Exam #1

The solutions content of this file below will be updated according to the instructions.

Solutions

The following sections contain a report on the solutions to each of the required components of this exam.

Data munging

The code in the Python program, solution.py, contains the solutions to the data munging part of this exam.

Spreadsheet analysis

The spreadsheet file, wifi.xslx, contains the solutions to the spreadsheet analysis part of this exam. In addition, the formulas used in that spreadsheet are indicated below:

1. Total number of free Wi-Fi hotspots in NYC

Place your formula here.

2. Number of free Wi-Fi hotspots in each of the 5 boroughs of NYC.

Place your formulas here - one on each line.

3. Number of free Wi-Fi hotspots provided by the Brooklyn Public Library in each of the zip codes of Brooklyn.

Place your formula for just the zip code 11201 here.

4. The percent of all hotspots in Brooklyn that are provided by the Brooklyn Public Library.

Place your formula here.

SQL queries

This section shows the SQL queries that you determined solved each of the given problems.

1. Write two SQL commands to create two tables named hotspots and populations.

Place your first command here.

Place your second command here.

2. Import the data in the wifi.csv and neighborhood_populations.csv CSV files into these two tables.

Place your first command(s) here.

Place your second command(s) here.

3. Display the five zip codes with the most Wi-Fi hotspots and the number of Wi-Fi-hotspots in each in descending order of the number of Wi-Fi-hotspots.

Place your query here.

4. Display a list of the name, location, and zip code for all of the free Wi-Fi locations provided by Transit Wireless in Manhattan, in ascending order of zip code.

Place your query here.

5. Display the names of each of the boroughs of NYC, and the number of free Wi-Fi hotspots in each.

Place your query here.

6. Display the number of wifi hotspots in Fort Greene, Brooklyn along with the population of Fort Greene, Brooklyn.

Place your query here.

7. Display the number of wifi hotspots in each of the 5 NYC boroughs, along with the population of each borough.

Place your query here.

8. Display the names of each of the neighborhoods in which there exist Wi-Fi hotspots, but for which we do not have population data.

Place your query here.

9. Write an additional SQL query of your choice using MySQL with this table; then describe the results

Write a description of the query here.

Place your query here.

Normalization and Entity-relationship diagramming

This section contains responses to the questions on normalization and entity-relationship diagramming.

1. Is the data in wifi.csv in fourth normal form?

Enter your response here

2. Explain why or why not the wifi.csv data meets 4NF.

Enter your response here

3. Is the data in neighborhood_populations.csv in fourth normal form?

Enter your response here

4. Explain why or why not the neighborhood_populations.csv data meets 4NF.

Enter your response here

5. Use draw.io to draw an Entity-Relationship Diagram showing a 4NF-compliant form of this data, including primary key field(s), relationship(s), and cardinality.