Question

The following is a line of R commands and the corresponding output for an object named “x” in an R Workspace: > class(x); dim(x); colMeans(x); length(x); mean(x); [1] ”data.frame” [1] 15 2 height weight 65.0000 136.7333 [1] 2 [1] NA Warning message: 1 In mean.default(x) : argument is not numeric or logical: returning NA ———— Using the above information, answer the following questions:

(a) How many variables are there in the object x? What are they?

(b) How many observations are there in the object x?

(c) What is the mean of x[,3]?

(d) Compute the sum of each column of x.

Answer #1

ans: there are 2 variables in x, which are height, weight

(b) How many observations are there in the object x?

ans:there are 15 observations in x

(c) What is the mean of x[,3]?

ans: There are only 2 columns in x, so mean of 3rd column can not
be calculated

(d) Compute the sum of each column of x.

ans: we know the average of each column, we also know that there
are 15 rows. using this we can calculate the sum

1st column=> sum/15=65.0000=> sum = 15*65=975

2nd column=> sum/15=136.7333=> sum=15*136.7333=2050.9995

Use R to do each of the following. Use R code instructions that
are as general as possible, and also as efficient as possible. Use
the Quick-R website for help on finding commands. 1. Enter the
following values into a data vector named Dat: 45.4 44.2 36.8 35.1
39.0 60.0 47.4 41.1 45.8 35.6 2. Calculate the difference between
the 2nd and 7th entries of this vector using only reference
indices. 3. Calculate the median of Dat. 4. Sort the...

Wenton Powersports produces dune buggies. They have three
assembly lines, “Razor,” “Blazer,” and “Tracer,” named after the
particular dune buggy models produced on those lines. Each assembly
line was originally designed using the same target production rate.
However, over the years, various changes have been made to the
lines. Accordingly, management wishes to determine whether the
assembly lines are still operating at the same average hourly
production rate.
Razor
Blazer
Tracer
11
10
9
10
8
9
8
9
10...

QUESTION 1 [13 MARKS]
Write down only the letter corresponding to your choice next to
the question number.
1.1. A random variable that can assume only a finite number of
values is referred to as a
a) Infinite sequence
b) Finite sequence
c) Discrete random variable
d) Discrete probability function
e) All of the above
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a) A data set provides information about people, objects or
other entities.
b) If the possible...

*Answer all questions using R-Script*
Question 1
Using the built in CO2 data frame, which contains data from an
experiment on the cold tolerance of Echinochloa crus-galli; find
the following.
a) Assign the uptake column in the
dataframe to an object called "x"
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Which one of the following statements about GLMs and GAMs is
FALSE?
a.An iterative algorithm is used to fit both GLMs and GAMs. That
is, it requires repeated computations that converge to the fitted
model
b.If a data frame is fed into glm() using the
data argument then if there are missing values in
any variable in the formula then, by default, that row is
deleted
c.The glm() function and gam()
function(s) models the mean response
d.For GAMs the coefficients...

Which one of the following statements about GLMs and GAMs is
FALSE?
a.An iterative algorithm is used to fit both GLMs and GAMs. That
is, it requires repeated computations that converge to the fitted
model
b.If a data frame is fed into glm() using the
data argument then if there are missing values in
any variable in the formula then, by default, that row is
deleted
c.The glm() function and gam()
function(s) models the mean response
d.For GAMs the coefficients...

Data
For Tasks 1-8, consider the following data:
7.2, 1.2, 1.8, 2.8, 18, -1.9, -0.1, -1.5, 13.0, 3.2, -1.1,
7.0, 0.5, 3.9, 2.1, 4.1, 6.5
In Tasks 1-8 you are asked to conduct some computations
regarding this data. The computation should be carried out
manually. All the steps that go into the computation should be
presented and explained. (You may use R in order to verify your
computation, but not as a substitute for conducting the manual
computations.)
A Random...

1) Consider the following Java program, which one of the
following best describes "setFlavor"?
public class Food {
static int count;
private String flavor = "sweet";
Food() { count++; }
void setFlavor(String s) { flavor = s; }
String getFlavor() { return flavor; }
static public void main(String[] args) {
Food pepper = new
Food();
System.out.println(pepper.getFlavor());
}
}
a. a class variable
b. a constructor
c. a local object variable
d....

1) Consider the following Java program. Which statement updates
the appearance of a button?
import java.awt.event.*;
import javax.swing.*;
public class Clicker extends JFrame implements ActionListener
{
int count;
JButton button;
Clicker() {
super("Click Me");
button = new
JButton(String.valueOf(count));
add(button);
button.addActionListener(this);
setSize(200,100);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
}
public void actionPerformed(ActionEvent e)
{
count++;
button.setText(String.valueOf(count));
}
public static void main(String[] args) { new
Clicker(); }
}
a. add(button);...

You will write a program that loops until the user selects 0 to
exit. In the loop the user interactively selects a menu choice to
compress or decompress a file. There are three menu options: Option
0: allows the user to exit the program.
Option 1: allows the user to compress the specified input file
and store the result in an output file.
Option 2: allows the user to decompress the specified input file
and store the result in an...

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