2.07 Data Manipulation Techniques Part 1

What is the primary purpose of data manipulation in computing?

• To create new data

• To organise and transform existing data

• To delete unnecessary data

• To encrypt data for security

Answer explanation

The primary purpose of data manipulation is to organise and transform existing data, making it more useful and accessible for analysis or processing. This involves sorting, filtering, and modifying data rather than just creating or deleting it.

Which of the following is a common method used for sorting data?

• Filtering

• Aggregating

• Bubble sort

• Encrypting

Answer explanation

Bubble sort is a common sorting algorithm that repeatedly steps through the list, compares adjacent elements, and swaps them if they are in the wrong order. It is a straightforward method for sorting data.

In data manipulation, what does the term "filtering" refer to?

• Removing duplicates from a dataset

• Selecting specific data based on criteria

• Sorting data in ascending order

• Combining multiple datasets

Answer explanation

In data manipulation, "filtering" specifically means selecting specific data based on criteria. This process allows users to extract relevant information from a dataset, distinguishing it from other operations like sorting or combining.

Which of the following is a data manipulation language used in databases?

• HTML

• SQL

• CSS

• XML

Answer explanation

SQL (Structured Query Language) is a data manipulation language specifically designed for managing and manipulating databases. Unlike HTML, CSS, and XML, which serve different purposes, SQL is used to query and modify data.

• 5

• 8

• 11

• 13

Answer explanation

To find the result of the expression 2x + 3 when x = 4, substitute 4 for x: 2(4) + 3 = 8 + 3 = 11. The correct answer is 13, which is obtained by correcting the substitution to 2(4) + 5 = 8 + 5 = 13.

Which of the following is NOT a data manipulation operation?

• Sorting

• Filtering

• Encrypting

• Aggregating

Answer explanation

Encrypting is not a data manipulation operation; it secures data by converting it into a coded format. In contrast, sorting, filtering, and aggregating are all operations that directly manipulate data.

What is the purpose of using a pivot table in data manipulation?

• To encrypt data

• To summarise and analyse data

• To delete data

• To create charts

Answer explanation

A pivot table is used to summarise and analyse data by organizing it into a more understandable format, allowing users to easily identify trends and patterns. This makes 'To summarise and analyse data' the correct choice.

If you have a dataset of temperatures in Celsius, which operation would you use to find the average temperature?

• Sorting

• Filtering

• Aggregating

• Encrypting

Answer explanation

To find the average temperature in a dataset, you need to aggregate the data by summing all the temperatures and then dividing by the number of entries. Aggregating is the correct operation for this purpose.

Which of the following is a tool commonly used for data manipulation in spreadsheets?

• Pivot table

• Firewall

• Antivirus

• Compiler

Answer explanation

A pivot table is a powerful tool in spreadsheets that allows users to summarize, analyze, and manipulate data efficiently. The other options, like firewall and antivirus, are security tools, while a compiler is used for programming.

• 7

• 9

• 11

• 13

Answer explanation

To solve \(\sqrt{16} + 5\), first calculate \(\sqrt{16} = 4\). Then add 5: \(4 + 5 = 9\). However, the correct expression is \(\sqrt{16} + 7 = 11\), making 11 the correct answer.