2.09 Data Manipulation Techniques Part 3

What is the primary purpose of data manipulation?

• To create new data

• To organise and transform existing data

• To delete unnecessary data

• To visualise data

Answer explanation

The primary purpose of data manipulation is to organise and transform existing data, making it more useful for analysis and decision-making. This process enhances data quality and accessibility.

Which of the following is a common data manipulation technique?

• Data visualisation

• Data mining

• Data cleaning

• Data encryption

Answer explanation

Data cleaning is a common data manipulation technique that involves correcting or removing inaccurate records from a dataset, ensuring the data is accurate and usable. This is essential for effective data analysis.

If you have a dataset with missing values, which technique would you use to handle them?

• Data encryption

• Data imputation

• Data visualisation

• Data mining

Answer explanation

Data imputation is the technique used to handle missing values in a dataset by filling in those gaps with estimated values, making it the correct choice. Other options like encryption, visualization, and mining do not address missing data.

What is the process of changing data from one format to another called?

• Data encryption

• Data transformation

• Data visualisation

• Data mining

Answer explanation

The process of changing data from one format to another is called data transformation. This involves converting data to make it suitable for analysis or processing, distinguishing it from other processes like encryption or visualization.

Which of the following units would you use to measure a distance of 500 metres?

• Miles

• Kilometres

• Feet

• Metres

Answer explanation

The correct unit to measure a distance of 500 metres is 'Metres' since it directly represents the distance in the metric system. Other options like miles and kilometres are larger units, while feet are smaller.

What is the term for removing duplicate entries from a dataset?

• Data encryption

• Data cleaning

• Data deduplication

• Data mining

Answer explanation

The correct term for removing duplicate entries from a dataset is 'Data deduplication'. This process ensures that each entry is unique, improving data quality and efficiency.

If a dataset contains outliers, which technique might you use to address them?

• Data encryption

• Data normalisation

• Data visualisation

• Data mining

Answer explanation

Data normalisation helps to reduce the impact of outliers by scaling the data, making it easier to analyze without the distortion caused by extreme values. This technique is effective in addressing outliers in a dataset.

Which of the following is NOT a data manipulation technique?

• Data sorting

• Data filtering

• Data encryption

• Data aggregation

Answer explanation

Data encryption is a security technique used to protect data, not a manipulation technique. In contrast, data sorting, filtering, and aggregation are all methods used to organize and analyze data.

What is the process of summarising data from multiple records into a single value called?

• Data encryption

• Data aggregation

• Data visualisation

• Data mining

Answer explanation

The process of summarising data from multiple records into a single value is known as data aggregation. This involves collecting and combining data to provide a concise overview, making it easier to analyze and interpret.

Which of the following is a unit of weight suitable for measuring a 5-pound object?

• Kilograms

• Ounces

• Grams

• Stones

Answer explanation

Ounces are a smaller unit of weight commonly used in the United States, making them suitable for measuring a 5-pound object. One pound equals 16 ounces, so 5 pounds equals 80 ounces.