Free SAS Institute A00-215 Practice Exam with Questions & Answers | Set: 3

In SAS, datasets can be either temporary or permanent, depending on the library where they are stored. Temporary datasets are stored in the Work library and are deleted at the end of the session, while permanent datasets reside in user-defined libraries or in libraries that refer to a more persistent storage location.

For this question:

• B. Mylib.new: This is a permanent dataset. The prefix 'Mylib' suggests it is stored in a user-defined library (not the temporary 'Work' library), implying that the data persists beyond the current session unless explicitly deleted or if the library's link to the storage location is removed.
• D. Temp.new: Despite the potentially misleading name 'Temp', if this dataset is not explicitly stored in the Work library, it could indeed be permanent. The permanence of a dataset is determined by its library reference, not by its name. If 'Temp' is a user-defined library linked to a persistent storage, then 'Temp.new' is also permanent.

C. Work.new: This dataset is explicitly temporary as it is stored in the Work library, which is cleared at the end of the SAS session.

A. New: Without additional context about the library, 'New' does not provide enough information to determine its permanence. It could be either temporary or permanent depending on the library it references.

References:SAS documentation on libraries and dataset management, SAS Institute.

The PROC MEANS statement is used to compute descriptive statistics of data in SAS. Option A is the correct code to produce the report shown in the first image because of the following reasons:

• data=sashelp.shoes specifies the dataset on which the procedure is to be performed.
• sum mean specifies that the summary statistics should include the sum and mean of the variables.
• var Sales; specifies that the variable Sales is the analysis variable for which the summary statistics are to be computed.
• class Product; specifies that the procedure should classify results by unique values of the Product variable. This will produce separate statistics for each type of product, which aligns with the structure of the report provided in the image.

Options B, C, and D are incorrect for the following reasons:

• B uses group instead of class, and group is not a valid statement in the context of PROC MEANS. Also, var Sale; is incorrect as the variable name is Sales.
• C includes nobe; which is not a valid SAS option and seems to be a typo. The by statement is used for sorting data, not for classifying groups as class does.
• D incorrectly uses sum Salad; and mean Sales; as separate statements and has an invalid use of by product; which is not needed here.

References:

• SAS 9.4 documentation for the PROC MEANS statement: SAS Help Center: PROC MEANS

In SAS, the SUBSTR function is used to extract a substring from a character string. The function syntax is SUBSTR(string, position, length), where:

• string is the variable or string literal you want to extract the substring from.
• position is the starting position of the substring within string.
• position starts counting at 1 in SAS, not 0 as in some other languages.
• length is the number of characters to extract.

For the value of date provided ("02Apr2019"), we want to extract the year, which is the four characters at the end of the string.

Here's how each option would work given the string:

A) year=substr(date, 7, 4);This starts at the 7th character of the string ("2019") and extracts 4 characters, which correctly represents the year.

B) year=substr(date, 4, 6);This starts at the 4th character ("Apr2019") and would extract 6 characters, which gives us "Apr201", not just the year.

C) year=substr(date, 6, 4);This starts at the 6th character ("r2019") and would extract 4 characters, resulting in "r201", which is not correct.

D) year=substr(date, 4, 7);This starts at the 4th character and would extract 7 characters, resulting in "Apr2019", which is the whole string from the 4th character to the end, not just the year.

The correct answer is A, as it extracts the four-digit year from the end of the string.

References:

• The SAS documentation on the SUBSTR function, which details how to use it for extracting parts of strings.
• SAS programming tutorials that often provide examples of common functions like SUBSTR for string manipulation