Which of the following query optimization techniques involves examining only the data that is needed for a particular task?
Correct Answer: C
Explanation The correct answer is C. Indexing documents. Indexing documents is a query optimization technique that involves creating a data structure that allows faster access to the data in the documents. Indexing documents can reduce the amount of data that needs to be scanned for a particular query, thus improving the performance and efficiency of the query. Indexing documents can also help with searching, sorting, filtering, and aggregating the data in the documents12
Question 127
A data analyst received the information in the table below from a recently completed marketing campaign: Which of the following is the total order conversion rate?
Correct Answer: B
The correct answer is A. 13.2%. The total order conversion rate is the ratio of the total number of orders to the total number of clicks, expressed as a percentage. To calculate the total order conversion rate, we need to sum up the clicks and orders from all the channels, and then divide the orders by the clicks and multiply by 100. Using the data from the table, we can do the following: * Total clicks = 580 + 800 + 1,200 + 300 + 620 = 3,500 * Total orders = 55 + 100 + 220 + 60 + 85 = 520 * Total order conversion rate = (520 / 3,500) x 100 = 14.857% * Rounding to one decimal place, we get 14.9% Therefore, the total order conversion rate is 14.9%.
Question 128
The duration of a phone call in milliseconds is an example of:
Correct Answer: D
Explanation The correct answer is D. Continuous data. Continuous data is a type of quantitative data that can take any value within a range and can be measured with infinite precision. Continuous data can be expressed as fractions, decimals, or percentages. Examples of continuous data are height, weight, temperature, time, speed, etc12 The duration of a phone call in milliseconds is an example of continuous data, because it can take any value within a range (from zero to infinity) and can be measured with infinite precision (up to milliseconds or even smaller units). The duration of a phone call in milliseconds can also be expressed as fractions, decimals, or percentages of a larger unit (such as seconds, minutes, or hours). Ordinal data is not correct, because ordinal data is a type of qualitative or categorical data that can be ordered or ranked according to some criterion. Ordinal data can have a logical order, but the intervals between the values are not equal or meaningful. Examples of ordinal data are grades, ratings, ranks, etc12 Nominal data is not correct, because nominal data is a type of qualitative or categorical data that can be labeled or named without any order or ranking. Nominal data can have a finite number of categories or classes, but the categories have no intrinsic value or hierarchy. Examples of nominal data are gender, color, nationality, etc12 Boolean data is not correct, because boolean data is a type of binary data that can have only two possible values: true or false. Boolean data can be used to represent logical statements, conditions, or outcomes. Examples of boolean data are yes/no, on/off, 1/0, etc.
Question 129
An analyst is building a new dashboard for a user. After an initial conversation with the user. the analyst created a mock-up of the dashboard. Which of the following best explains why the analyst created the mock- up?
Correct Answer: C
To confirm important details before dashboard development begins. A dashboard mockup is a prototype of a finished dashboard directly in the product. It is a way to visualize the layout, design, and functionality of the dashboard before it is built with real data and code. A dashboard mockup can help the analyst to confirm important details with the user, such as the business objectives, the key performance indicators, the data sources, the filters, the charts, and the interactivity.By creating a dashboard mockup, the analyst can get immediate feedback and validation from the user,and avoid wasting time and resources on developing a dashboard that does not meet the user's expectations or needs1.
Question 130
An analyst has generated a report that includes the number of months in the first two quarters of 2019 when sales exceeded $50,000: Which of the following functions did the analyst use to generate the data in the Sales_indicator column?
Correct Answer: B
This is because a logical function is a type of function that returns a value based on a condition or a set of conditions. A logical function can be used to generate the data in the Sales_indicator column by comparing the values in the Sales column with a threshold of $50,000 and returning either "Exceeded $50,000" or "Not exceeded $50,000" accordingly. For example, a logical function in Excel that can achieve this is: The other functions are not suitable for generating the data in the Sales_indicator column. Here is why: Aggregate is a type of function that performs a calculation on a group of values, such as sum, average, count, etc. An aggregate function cannot generate the data in the Sales_indicator column because it does not compare the values in the Sales column with a threshold or return a text value based on a condition. Date is a type of function that manipulates or extracts information from dates, such as year, month, day, etc. A date function cannot generate the data in the Sales_indicator column because it does not use the values in the Sales column or return a text value based on a condition. Sort is a type of function that arranges the values in a column or a range in ascending or descending order. A sort function cannot generate the data in the Sales_indicator column because it does not create a new column or return a text value based on a condition.
