Free Practice Questions for CompTIA DA0-001 Exam

Optimizing the dashboard is the process of improving its performance and reducing its loading time by applying various techniques and best practices. Some of the common ways to optimize a dashboard are:

Reducing the size and complexity of the data model, such as removing unnecessary columns, aggregating data at the source, or using data compression techniques12

Leveraging caching strategies, such as setting appropriate cache refresh intervals or utilizing Power BI’s built-in caching mechanisms, to minimize data retrieval delays2

Utilizing query folding, direct query, or live connection to enhance data processing efficiency and enable real-time data updates23

Optimizing DAX queries, such as avoiding nested calculations, using variables, or simplifying measures, to improve data calculation speed23

Reducing visualizations and calculations, such as using fewer or simpler charts, filters, or parameters, to speed up dashboard rendering12

Evaluating the impact of custom visuals on dashboard load time and avoiding or replacing those that are slow or inefficient2

Applying aggregation and summarization techniques, such as using extract filters, context filters, or level of detail expressions, to reduce the amount of data displayed on the dashboard1

Troubleshooting and resolving any issues that may cause slow dashboard load, such as network latency, server overload, or hardware limitations24

Adata dictionaryis the best resource for understanding what data an organization possesses. It providesmetadataabout datasets, including:

Field names and definitions

Data types (e.g., numeric, text, Boolean)

Allowed values and constraints

Relationships between different data fields

Option A (Data destruction policy):Incorrect. This document outlines procedures for securely deleting data but does not describe the data the organization currently possesses.

Option B (Data use document):Incorrect. This document explains how data should be used but does not provide a comprehensive inventory of available data.

Option C (Data dictionary):Correct.The data dictionary is a structured reference that describes all available data assets within an organization.

Option D (Data retention policy):Incorrect. This policy dictates how long data is stored but does not provide details about what data exists.

Discrete data is a type of data that can only take certain values, usually whole numbers or integers. Discrete data can be counted, but not measured. For example, the number of students in a class, the number of books in a library, or the number of phone calls that a call center receives in a day are all examples of discrete data. Discrete data is different from continuous data, which can take any value within a range, and can be measured with precision. For example, the height of a person, the weight of a fruit, or the temperature of a room are all examples of continuous data. Therefore, the correct answer is D. References: [Discrete vs Continuous Data: Definition and Examples - Statistics How To], [Discrete Data - Definition and Examples | Math Goodies]

The median is recognized as the most appropriate measure of central tendency when outliers have been removed from a dataset. This is because the median is less influenced by extreme values compared to the mean. When outliers are present, they can significantly skew the mean, making it an unreliable measure of central tendency. The median, on the other hand, is the middle value of a dataset when ordered from least to greatest and remains unaffected by the extremes. Therefore, it provides a better representation of the central location of the data after outliers have been excluded.

Explanation

A measure of central tendency (also referred to as measures of centre or central location) is a summary measure that attempts to describe a whole set of data with a single value that represents the middle or centre of its distribution.

There are three main measures of central tendency: the mode, the median and the mean. Each of these measures describes a different indication of the typical or central value in the distribution.

What is the mode?

The mode is the most commonly occurring value in a distribution.

The most commonly occurring value is 54, therefore the mode of this distribution is 54 years.

Qualitative data refers to non-numeric information that describes qualities or characteristics. It is often categorized based on attributes or properties and is typically descriptive in nature.

Ordinal Data:This type of qualitative data represents categories with a meaningful order but without a consistent interval between them. Examples include rankings (e.g., customer satisfaction levels such as 'satisfied,' 'neutral,' 'dissatisfied') where the order matters, but the difference between ranks is not uniform.

Nominal Data:This qualitative data type consists of categories without any inherent order. Examples include gender, race, or types of products. Each category is distinct, and there is no logical sequence.

In contrast, options A (Discrete) and D (Continuous) refer to quantitative data types:

Discrete Data:Quantitative data that can take on only specific, distinct values (e.g., the number of students in a class).

Continuous Data:Quantitative data that can take on any value within a range (e.g., height, weight).

Options C (Batch) and F (Real-time) pertain to data processing methods rather than data types.

A confidence interval provides a range within which we expect a population parameter to lie, based on sample data. Increasing the confidence level means we want to be more certain that the interval contains the parameter, which affects the margin of error.

Option A:The margin of error does not change.

Rationale:This is incorrect. Increasing the confidence level requires a wider interval to maintain the higher degree of certainty, which increases the margin of error.

Option B:The interval remains the same.

Rationale:This is incorrect. To achieve a higher confidence level, the interval must widen, altering its range.

Option C:The interval becomes narrower.

Rationale:This is incorrect. A higher confidence level necessitates a wider interval to ensure the parameter is captured within the range.

Option D:The margin of error increases.

Rationale:Correct. Increasing the confidence level from 90% to 95% means we are more confident that the interval contains the true parameter. To achieve this increased confidence, the margin of error must increase, resulting in a wider interval.