Professor Y. Doncha Findwork is in charge of placement of graduate students from the Barzini Institute of Business and Public Affairs (Sicily). Her goal is to find great job offers for students that they cannot refuse. Professor Findwork follows up with students one year post-placement to see if they are satisfied with their positions. She wants to know how effective the placements have been, as measured by student satisfaction. Help Professor Findwork by analyzing the data she has collected below. Are students more satisfied with placements in certain types of organizations more than others? In what types of organizations would you advise Professor Findwork to place her students? Calculate lambda and interpret its meaning.

In a certain high school, uniforms are optional. A study shows that high school students who wear uniforms have a lower grade average than students who don't wear uniforms. From this study, the school administration claims that they should not require the students to wear uniforms because that is the cause of the lowering grades. Another possible explanation is that students who wear uniforms are poorer than the students who don't wear uniforms and the economic situation of their parents is causing the lower grades.

a) What is the explanatory variable in this study?
economic situation
poorer grades.
wearing a uniform.

b) What is the response variable in this study?
economic situation
wearing a uniform.
poorer grades.

c) What is the lurking variable in this study?
poorer grades.
wearing a uniform.
economic situation

d) Draw a diagram that explains your answers. (Possible diagrams are causation, common response, or confounding). Be sure to label all variables in the diagram

A teacher assigns a group of 30 students into 3 groups of 10. The way the assignment process works is as follows: the teacher first randomly picks 10 students from the class and assigns them to group 1; from the remaining group of students that have not been assigned, the teacher randomly picks 10 more and assigns them to group 2; finally, the remaining students not yet picked are all assigned to group 3. Henry and Marcel are friends and desperately want to be in the same group. To improve their chances, they quickly hide behind a cabinet, unnoticed, just before the teacher starts picking students. Immediately after the teacher has picked the 12th student, Henry quietly returns to his seat. Immediately after the teacher has picked the 16th student Marcel quietly returns to his seat. What is the probability that Henry and Marcel will be selected for the same group, and did they in fact improve their odds compared to simply staying in their seats the entire time?

Three statistics students are having a discussion about selecting the appropriate distribution for a data set. Explain why you agree or disagree with each student and give your own suggestion for the approach the students should take.

Maya: Maya argues that since the students don’t know what the population data looks like they should simply use the sample probability mass distribution as their population mass distributions.

Greg: Greg says that the sample probability mass distribution is oddly shaped and will almost certainly not be the same as the population mass distribution function. He suggests that it’s best to find a match from the common probability mass functions that the students know about.

Jane: Jane argues that both Greg and Maya’s approach could introduce unknown error into the analysis that they are performing. She reasons that as long as there is going to be error, the students should try both approaches and choose the one that produces the results that they would most like to see.

Suppose that the amount of time that students spend studying in the library in one sitting is normally distributed with mean 43 minutes and standard deviation 17 minutes. A researcher observed 43 students who entered the library to study. Round all answers to 4 decimal places where possible.

What is the distribution of X?X ~ N(,)

What is the distribution of x¯? x¯ ~ N(,)

What is the distribution of ∑x? ∑x ~ N(,)

If one randomly selected student is timed, find the probability that this student's time will be between 41 and 44 minutes.

For the 43 students, find the probability that their average time studying is between 41 and 44 minutes.

Find the probability that the randomly selected 43 students will have a total study time more than 1978 minutes.

The top 20% of the total study time for groups of 43 students will be given a sticker that says "Great dedication". What is the least total time that a group can study and still receive a sticker? _minutes

1. According to an educational report, the amount of time that students spend “off-task” (such as by checking their phones) during a one-hour lecture is approximately normally distributed with a mean of 3.2 minutes and a standard deviation of 2.7 minutes. An educator is interested in determining at the α = 0.05 level if the average amount of time his students spend on their phones while he is lecturing differs from the value given in the journal. During a particular class period in which he has 37 students, he noted that the average amount of time students spent on their phones was 4.2 minutes.

(a) State the null and alternative hypotheses for this test.

(b) Compute an appropriate test statistic.

(c) Determine the p-value for this test.

(d) State, in words, your conclusion.

2. Construct a 95% confidence interval for the mean amount of time students spend on their phones. Does this confidence interval support your conclusion from the hypothesis test in part (d)? Why or why not?

Database Design and SQL

Consider the following relations:

Student (snum: integer, sname: string, major: string, level: string, age: integer)
Class (name: string, meets_at: time, room: string, fid: integer)
Enrollment (snum: integer, cname: string)
Faculty (fid: integer, fname: string, deptid: integer)

Write the following queries in SQL. Also, there should be no duplicates printed in any of the answers.

a) Find the names of all students who are enrolled in two classes that meet at the same time.
b) Find the names of faculty members for whom the combined enrollment of the courses that they teach is less than five.
c) Print the Level and the average age of students for that Level, for each Level.
d) Print the Level and the average age of students for that Level, for all Levels except JR.
e) Find the names of students who are enrolled in the maximum number of classes.
f) Find the names of students who are not enrolled in any class.

----fix code to search and delete a student by Identification number

import java.util.Scanner;

public class COurseCom666 {

    private String courseName;
    private String[] students = new String[1];
    private int numberOfStudents;

    public COurseCom666(String courseName) {
        this.courseName = courseName;
    }

    public String[] getStudents() {
        return students;
    }

    public int getNumberOfStudents() {
        return numberOfStudents;
    }

    public String getCourseName() {
        return courseName;
    }

    public int DeleteStudentsByID() {
        return deleteStudentByID();
    }

    public void addStudent(String student) {

        if (numberOfStudents == students.length) {
            String[] a = new String[students.length + 1];
            for (int i = 0; i < numberOfStudents; i++) {
                a[i] = students[i];
            }
            students = a;
        }
        students[numberOfStudents] = student;
        numberOfStudents++;
    }

    public String[] addStudentByIndex(String student, int index) {
        String[] a = new String[students.length + 1];
        if (numberOfStudents == students.length) {
            for (int i = 0; i < a.length; i++) {
                if (i < index) {
                    a[i] = students[i];
                } else if (i == index) {
                    a[i] = student;
                } else {
                    a[i] = students[i - 1];
                }
            }
        }
        numberOfStudents++;
        return a;
    }

    public static void display(String[] students) {
        System.out.println("========================");
        System.out.print("Now the New students Array is : \n");
        for (int i = 0; i < students.length; i++) {
            System.out.println("Index: " + (i) + "--> " + students[i] + " ");
        }
    }

    public String[] removeStudentByIndex(String[] a, int index) {

        String[] b = new String[a.length - 1];
        students = a;

        for (int i = 0, k = 0; i < a.length; i++) {
            if (i == index) {
                continue;
            } else {
                b[k++] = a[i];
            }
        }
        numberOfStudents--;
        return b;

    }

    public int[] deleteStudentByID(int num[]) {

    }


    private int findStudent(String student) {
        for (int i = 0; i < numberOfStudents; i++) {
            if (students[i].equals(student)) {
                return i;
            }
        }
        return -1;
    }
}

import java.util.Scanner;

public class d {

    public static void main(String[] args)
    {
        COurseCom666 com666 = new COurseCom666("com666");
        com666.addStudent("Bishal");
        com666.addStudent("Ana");
        com666.addStudent("Ying");
        com666.addStudent("Samuel");
        com666.addStudent("Surai");
        int sum = 0;

        String students1[] = com666.getStudents();
        sum += com666.getNumberOfStudents();
        Scanner scan = new Scanner(System.in);

        int choice;

        do {
            System.out.println("Welcome to St.Joseph's College");
            System.out.println("1. View Student");
            System.out.println("2. Insert Student");
            System.out.println("3. Remove a student");
            System.out.println("4. Delete a student by ID");
            System.out.println("5. Exit");
            choice = scan.nextInt();
            if (choice == 1)
            {
                for (int i = 0; i < students1.length; i++)
                {
                    System.out.println("Index is: " + (i) + "---> " + students1[i]);
                }
                System.out.println("Number of students attending the Course is: " + sum);
            }
            else if (choice == 2)
            {
                System.out.println("Enter the name of student and index: ");
                scan.nextLine();
                String student = scan.nextLine();
                int index = scan.nextInt();
                students1 = com210.addStudentByIndex(student, 3);
                com666.display(students1);
                sum = com666.getNumberOfStudents();
                System.out.println("After student was added number is: " + sum);
            }
            else if (choice == 3) {
                System.out.println("Remove a student by index");
                int index = scan.nextInt();
                students1 = com666.removeStudentByIndex(students1, index);
                com666.display(students1);
                sum = com666.getNumberOfStudents();
                System.out.println("After student drop number is: " + sum);
                System.out.println("Number of students attending the Course is: " + sum);
                System.out.println("----------------------------------");
            }
            else if (choice ==4) {
                System.out.println("Delete a students ID");

                System.out.println("Bishal", StudentID);
                String student1_name = "Bishal";
                int StudentID = 111111;

                System.out.println("Ana", StudentID);
                String student2_name = "Ana";
                int StudentID = 222222;


                String student3_name = "Ying";
                int StudentID = 333333;

                String student4_name = "Samuel";
                int student4_id = 444444;

                String student5_name = "Surai";
                int student5_id = 555555;



            }


        }
        while (choice!= 5);
    }
}

Credit for Students

Credit card vendors are allowed to setup booths on campus at the beginning of each semester. Students are enticed to apply for credit cards through various "offers" (Free tee-shirts, coffee mugs, etc.).

Is this a good thing? Discuss your answer in terms of what the students get, what the vendors get and what the campus (student organizations) may get.

In addition, with all this "getting", are there any potential problems?

At Case Western Reserve University, 46.6% of the student body are undergraduates and 53.4% of those enrolled are graduate students. 60.7% of undergraduate students participate in extracurricular activities, while only 32.1% of graduate students participate in extracurricular activities. A student who participates in extracurricular activities is randomly selected. What is the probability that the student is an undergraduate? Use Baye’s theorem to solve this problem. (Write your answer as a percent rounded to 1 decimal place.)