Pass the CompTIA CompTIA Data+ DA0-001 Questions and answers with CertsForce

Themedianis the middle value in a sorted list of numbers. The steps to determine the median are:

Sort the numbers in ascending order:3, 5, 6, 7, 9

Find the middle value:Since there arefivenumbers, the middle value is the third one:Median = 6

Option A (5):Incorrect. 5 is not the middle value.

Option B (6):Correct.6 is the middle value in the sorted list.

Option C (7):Incorrect. 7 is not the middle value.

Option D (9):Incorrect. 9 is the highest value, not the median.

For efficient data manipulation, the ideal order would be to first merge related tables to create a comprehensive set of records, then deduplicate to remove any redundant information. Lastly, appending additional data, such as from another source or table, ensures that all relevant data is included without redundancy before the final analysis. This order prevents unnecessary duplication of effort, such as deduplicating both before and after appending, which would be less efficient.

In the context of the tables provided, merging would likely involve combining customer information from the online and in-store transaction tables with the customer table. Deduplication would remove any redundant customer records that may exist across these tables. Finally, appending would involve adding any additional transaction records to the master file, ensuring a complete dataset for analysis.

The correct join the analyst should complete is B. LEFT JOIN, four rows.

A LEFT JOIN is a type of SQL join that returns all the rows from the left table, and the matched rows from the right table. If there is no match, the right table will have null values.A LEFT JOIN is useful when we want to preserve the data from the left table, even if there is no corresponding data in the right table1

Using the example tables, a LEFT JOIN query would look like this:

SELECT t1.Name, t1.City, t2.Age FROM Table1 t1 LEFT JOIN Table2 t2 ON t1.Name = t2.Name;

The result of this query would be:

Name City Age Jane Smith Detroit NULL John Smith Dallas 34 Candace Johnson Atlanta 45 Kyle Jacobs Chicago 39

As you can see, the query returns four rows, one for each name in Table1. The name John Smith appears twice in Table2, but only one of them is matched with the name in Table1. The name Jane Smith does not appear in Table2, so the age column has a null value for that row.

The answer is A. Outlier.

Short explanation: An outlier is a data point that differs significantly from the rest of the data in a dataset. An outlier can indicate an error, an anomaly, or a rare event in the data.An outlier can affect the statistical analysis and visualization of the data, such as skewing the mean, variance, or distribution of the data. Therefore, data should be cleaned to identify and remove or correct any outliers.

The image below shows a box plot graph with a vertical axis labeled “Customer Calls” and a horizontal axis labeled “Churn”. The box plot is blue in color and the median value is around 2. There are 7 outliers above the box plot, ranging from 4 to 8.

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A box plot is a type of graph that can show the distribution of data values using five summary statistics: minimum, maximum, median, first quartile, and third quartile. The box represents the interquartile range (IQR), which is the difference between the first and third quartiles. The median is shown as a line inside the box. The whiskers extend from the box to the minimum and maximum values, excluding any outliers. Outliers are shown as dots or circles outside the whiskers.

In this graph, we can see that most of the customer calls are between 0 and 4, with a median of 2. However, there are 7 outliers that have more than 4 customer calls, up to 8. These outliers may indicate some customers who have more issues or complaints than others, or some errors or anomalies in the data collection or recording process. These outliers can affect the analysis and interpretation of the customer calls and churn relationship, such as making it seem that more customer calls lead to less churn, which may not be true for the majority of the customers. Therefore, data should be cleaned to investigate and handle these outliers appropriately.

To compare two quantitative variables, the classic best choice (when available) is a scatter plot. In this version of the question, however, scatter plot is not one of the options. Among the given choices:

Bar graph – typically compares a categorical variable (categories on the x-axis) against a quantitative measure (bar height). It is not ideal for two purely quantitative variables.

Histogram – is designed to show the distribution of a single quantitative variable, not the relationship between two quantitative variables.

Pie chart – is used to show proportions of a whole and is not appropriate for comparing two quantitative variables directly.

Heat map (B) – can be used to display the relationship between two dimensions (which can be numeric) by using color intensity to encode the magnitude of a third variable or frequency of combinations. It is the best fit among the given choices for visualizing relationships across pairs of numeric values when a more suitable plot (like scatter) is not provided.

So, from the options listed here, Heat map (B) is the most appropriate to represent a relationship between two quantitative variables.

Note: In many CompTIA Data+ practice items that do include a scatter plot option, that is normally the correct choice for “two quantitative variables.” Here, with the restricted options, heat map is the best available match.

CompTIA Data+ Reference (concept alignment):

CompTIA Data+ Official Exam Objectives – Domain on Visualization (choosing appropriate visualizations for different data types).

CompTIA Data+ Official Study Guide – section distinguishing bar charts, histograms, pie charts, and heat maps, and their use cases.

Analyzing relationships between authors based on citation patterns involves understanding the connections and interactions within a network of entities.Link analysisis the appropriate technique for this purpose.

Option A:Linguistic analysis

Rationale:Linguistic analysis focuses on the structure and meaning of language within the text. While it can provide insights into the content of the papers, it doesn't address the relationships between authors.

Option B:Trend analysis

Rationale:Trend analysis examines data over time to identify patterns or trends. It doesn't specifically focus on the relationships or connections between entities, such as authors citing each other.

Option C:Link analysis

Rationale:Link analysis evaluates relationships and interactions between nodes in a network. In the context of research papers, it can be used to map and analyze how authors cite one another, revealing influential authors, collaboration networks, and the flow of ideas.

The RefNo column contains values that consist solely of digits without any alphabetical characters or special symbols, indicating a numeric data type.

Explanation

Simply put, a z-score (also called a standard score) gives you an idea of how far from the mean a data point is. But more technically it's a measure of how many standard deviations below or above the population mean a raw score is. A z-score can be placed on a normal distribution curve.