IKM Data Analysis and Business Intelligence 2

Question 1

Which SQL aggregate function would you use to count the number of non-NULL values in a column?

Accepted Answer

COUNT()

Answer

COUNT(column_name) returns the number of rows where the specified column is not NULL, making it the correct function for counting non-null values.

Question 2

What is a 'pivot table' used for in data analysis tools like Excel or Power BI?

Accepted Answer

Summarizing and reorganizing data to identify patterns and trends

Answer

A pivot table dynamically summarizes, groups, and aggregates large datasets, allowing analysts to reorganize rows and columns to reveal patterns and trends quickly.

Question 3

Which chart type is most appropriate for showing the distribution of a single continuous variable?

Accepted Answer

Histogram

Answer

A histogram groups continuous data into intervals (bins) and displays the frequency of values in each bin, making it ideal for visualizing the distribution of a single variable.

Question 4

In data analysis, what does the term 'data granularity' refer to?

Accepted Answer

The level of detail or precision at which data is stored or reported

Answer

Data granularity refers to the level of detail in data records — fine granularity means each row represents a single transaction, while coarse granularity means rows represent daily or monthly summaries.

Question 5

A correlation coefficient of -0.92 between two variables indicates which of the following?

Accepted Answer

A strong negative linear relationship

Answer

A correlation coefficient close to -1 (such as -0.92) indicates a strong negative linear relationship, meaning as one variable increases, the other tends to decrease significantly.

IKM - International Knowledge Measurement Practice Test

IKM - International Knowledge Measurement Practice Test

IKM Data Analysis and Business Intelligence 2