Answer:
C. sending emails impersonating legitimate companies in an attempt to learn a recipient's personal information
Answer:
The solution code is written in R script.
- #string variable
- character_str<- "Hello World"
- #logical variable
- logic <- a > b
- #Missing value
- myVec <-c(1, 2, 3, NA)
- #Use class to check data type
- class(character_str)
- class(logic)
- class(myVec)
Explanation:
A string variable is a variable that hold a string (the letters enclosed within quotation marks) (Line 2)
A logical variable is a variable that hold a logical value (either True or False). The logical value is created by comparing two variables (Line 5).
In R, missing value is an unknown value which is represented by NA symbol (Line 8).
We can use in-built method <em>class </em> to check for the variable type in R (Line 11-13). For example, the output of <em>class(character_str)</em> is "<em>character</em>"
Answer:
1. the set of real numbers between 0.1 and 0.2
2. the set of all negative integers greater than negative 1 trillion
3. the set of all java and C programs
Explanation:
A set is countable if it is either finite or has the same cardinality as the set of positive integers. The inverse of this set type is uncountable.
The set of real numbers between 0.1 and 0.2, all negative integers greater than negative 1 billion, and a set of java and C programs are all countable sets, so are considered countably infinite.
Answer:
a. True
Explanation:
The three tiers in a three-tier architecture are:
Presentation Tier: Occupies the top level and displays information related to services available on a website. This tier communicates with other tiers by sending results to the browser and other tiers in the network.
Middle Tier: Also called the application tier, logic tier, business logic or logic tier, this tier is pulled from the presentation tier. It controls application functionality by performing detailed processing.
Data Tier: Houses database servers where information is stored and retrieved. Data in this tier is kept independent of application servers or business logic.
