Which of the following describes the method of sampling in which elements of data are
selected randomly from each of the small subgroups within a population?
Correct Answer:D
This is because stratified is a type of sampling in which elements of data are selected randomly from each of the small subgroups within a population, such as age groups, gender groups, or income groups. Stratified sampling can be used to ensure that the sample is representative and proportional of the population, as well as reduce the sampling error or bias. For example, stratified sampling can be used to select a sample of voters from different political parties based on their proportion in the population. The other types of sampling are not the types of sampling in which elements of data are selected randomly from each of the small subgroups within a population. Here is why:
✑ Simple random is a type of sampling in which elements of data are selected randomly from the entire population, without dividing it into any subgroups. Simple random sampling can be used to ensure that every element in the population has an equal chance of being selected, as well as avoid any systematic error or bias. For example, simple random sampling can be used to select a sample of students from a school by using a lottery or a computer-generated number.
✑ Cluster is a type of sampling in which elements of data are selected randomly from
a few large subgroups within a population, such as regions, districts, or schools. Cluster sampling can be used to reduce the cost and complexity of sampling, as well as increase the feasibility and convenience of sampling. For example, cluster sampling can be used to select a sample of households from a few neighborhoods by using a map or a list.
✑ Systematic is a type of sampling in which elements of data are selected at regular
intervals from an ordered list or sequence within a population, such as every nth element or every kth element. Systematic sampling can be used to simplify and speed up the sampling process, as well as ensure that the sample covers the entire range or scope of the population. For example, systematic sampling can be used to select a sample of books from a library by using an alphabetical order or a numerical order.
An analyst is creating a resource to improve users' experience when they select specific records based on particular dates. Which of the following should the analyst use to create a resource that best meets user needs?
Correct Answer:B
A drop-down menu is a graphical user interface element that allows users to select one option from a list of options that are hidden until the user clicks on the menu. A drop-down menu can be used to create a resource that best meets user needs when they select specific records based on particular dates, because:
✑ A drop-down menu can provide a predefined list of dates or date ranges that are relevant and valid for the records, such as today, yesterday, last week, last month, custom range, etc. This can help users to avoid typing errors or invalid dates in a text field, and to save time and effort in entering the dates.
✑ A drop-down menu can also provide a calendar or a date picker that allows users
to select a specific date or a range of dates from a graphical representation of a calendar. This can help users to visualize and compare the dates, and to easily adjust or modify their selection.
✑ A drop-down menu can improve the user experience by making the interface more
compact and organized, as it only shows one option at a time and hides the rest of the options until the user clicks on the menu. This can help users to focus on their selection and to avoid clutter and distraction.
Which of the following is most likely to be used as a data-mining ETL tool?
Correct Answer:A
Which of the following is a relational database?
Correct Answer:A
The total values in this month's revenue report are twice as much as last month's. Which of the following most likely occurred during the ETL process?
Correct Answer:C