# Is This Statement True About Data Usage

Which statement about a histogram is true? HELP?

I really need help on this Answer!! I don't get it

Question:Which statement about a histogram is true?

A:Histograms can plot both positive and negative values on both axes.

B:Histograms can be used to exhibit the shape of distributions.

C:Histograms are plots of individual data values.

D:Histograms show the division of quartile regions for a distribution.

Which statement is true about port numbers?

A) Source port and destination port numbers are not necessary when UDP is the transport layer protocol being used for the communication.

B) Source port and destination port numbers are randomly generated.

C) If multiple conversations occur that are using the same service, the source port number is used to track the separate conversations.

D) Destination port numbers are assigned automatically and cannot be changed.

Is it good to use return true and return false statements in the for loop?

Yes, why not.Actually, it depends on the usage and the requirements of the program you are writing. Let us assume you have to find whether a number exists in a given array or not.One way of doing it to iterate the complete array and check for the occurrence in the array, and store the result in a boolean variable. If found, break the for loop and then return the value of your boolean variable. static boolean checkNuminArr(int [] arr, int n){

boolean found = false;
for (int i=0,len=arr.length;++i if (arr[i] == n)
found = true;
break;
}
return found;
} Another, simple way which I would prefer in this particular example would be to avoid the usage of an extra boolean variable and hence saving a fraction of memory. static boolean checkNuminArr(int [] arr, int n){

for (int i=0,len=arr.length;++i if (arr[i] == n)
return true;

}
return false;
} Note that the time complexity of both the implementations is identical but in the second one we are avoiding the use of an additional boolean.PS: The usage actually depends on the requirement. In the example given in your question description, it seems good. Using break would make it look ugly and also doesn't do any value addition (semantics wise).

Which statement is true about a frequency distribution?

3. Which statement is true about a frequency distribution?
It is the same as a histogram.
It shows the comparison of two groups of data.
It can show three or more aspects of data at the same time.
It is a convenient system for organizing data.
4. Which statement is not true about the class intervals in a frequency distribution?
A class interval is the range of each class.
Each class interval should have a different range.
Class intervals are represented by the width of each bar in a histogram.
Each class interval has upper and lower values.

If a statement about a particular race is true, is it still a racist statement? For example, I have often heard that most serial killers are white males. IF that is true, is that a racist or sexist statement?

Data statements that are objectively true can be used for neutral purposes. Or they can be used for racist purposes. It depends on two factors.What makes the difference is the elaboration that accompanies the fact. Plus the criteria used to produce the information.One race may indeed be involved in a certain crime more than other races. The elaboration of this basic fact into a theory "proving the intrinsic inferiority"of that group is bigotry.Also: the criteria used to produce the data can be consciously or unconsciously biased.It is a fact that Black people as a total group commit street crime to a higher degree than White people as a total group.But if you correct for poverty, it is clear that race has little to do with the commission of street crime. Upper class and Middle class Blacks have zero tendency towards crime. Poor Black involvement in street crime is a function of poverty. Higher rates of criminality reflect higher rates of poverty. In this case, analyzing the objective data based on economic facts, the conclusion changes.White males commiting serial murder at a higher rate is probably an objective fact. It is neutral data.However, if you elaborate it into a theory that the White race is bloodthirsty and intrinsically violent, that is bigotry.You would also need to look at the data from various angles. Is there another factor that is dispositive? Is the data even irrelevant?Since there are only a few dozen serial killers at any given time, in a nation of 300 million, any facts derived from this tiny group dont say much in reference to the larger society.

What should be the data type of case labels of switch statement in c?

Case labels of switch statement in C can be any of the following:Integer.Character.Short or Long.Expression - Which evaluates to a constant value.Macro Identifiers.Constant Variable.Data types used as case labels of switch statement in C are integer,short,long and character.Float and Double can’t be used as case labels.

How true is this statement: "The emerging trend is that JavaScript, Ajax, and NoSQL is in the process of leaving PHP and MySQL in the dust"?

I find the statement a bit strange and not necessarily logical, or at best, not very accurate. To explain, lets first look at what these different technologies are used for:"The old":MySQL saves and holds the data, and enables you to get the data you want with a query.PHP serves at the "glue" between the data and how it is presented (it may also be used for more advanced tasks, of course). Runs server side."The new":JavaScript is mainly used as a client side scripting language, to e.g. manipulate the DOM (HTML), which might be served by PHP.AJAX is a technique that is used within JavaScript to communicate with something server side, that might be served by e.g. PHP.NoSQL, not-only-SQL keeps and serves the data.To summarize, the person's statement lacks the server side layer as the glue between the database and the client side (JavaScript+HTML).Although you now have the ability to run JavaScript server side as well, by using node.js, I suspect this person didn't mean that.I belive both PHP and MySQL will live well and be used for new and amazing web apps for many years to come, but PHP might not be the one who's rendering everything you see. I think PHP mostly will serve as an API engine that JavaScript communicates with (using AJAX), and that JavaScript will be the one who renders what you see and interact with.With NoSQL vs. MySQL, I don't know...

Which three statements are true about transport layer protocols? (Choose three.)?

1,2,3
Here's why:
1. UDP provides low overhead data delivery but at the expense of reliability. The receiving host never acknolodges whether or not it received a data segment (this is called connectionless).
2. TCP uses windowing and acknowledgements to ensure all data segments arrive at the host. Any missing segments are re-transmitted by the sender (this is called connection-oriented).
3. TCP and UDP port numbers are indeed used by application layer protocols. You can view it in the OSI model here:
http://www.dmccormick.org/tcpip.htm
4. Routing and addressing for packet direction happens at the network layer not the transport layer.
5. UDP is connectionless not connection oriented.
6. UDP has no mechanism to check if data segments are lossed. Again this is because it's connectionless.

Which of the following statements is not true with respect to pie charts?

A. A circle is drawn to represent the entire data set when constructing a pie chart.
B. A pie chart is used with quantitative data sets.
C. A pie chart can be used for a data set with a relatively small number of possible categories.
D. Pie charts are most useful for illustrating proportions of the whole data set for various categories.