A university posts its employee salary at http://cs .armstrong.edu/liang/data/Salary.txt. Each line in the file consists of faculty first name, last name, rank, and salary. Write a program to display the total salary for assistant professors, associate professors, full professors, and all faculty, respectively, and display the average salary for assistant professors, associate professors, full professors, and all faculty, respectively.

True or false, and explain briefly: a) If the correlation coefficient is -0.80, below-average values of the dependent variable are associated with below-average values of the independent variable. b) If y is usually less than x, the correlation coefficient between x and y will be negative.

In a study of 2005 Math SAT scores, the Educational Testing Service computed the average score for each of the 51 states, and the percentage of the high-school seniors in that state who took the test. (For these purposes, D.C. counts as a state.) The correlation between these two variables was equal to -0.84. a) True or false: test scores tend to be lower in the states where a higher percentage of the students take the test. I true, how do you explain this? If false, what accounts for the negative correlation? b) In Connecticut, the average score was only 517. But in Iowa, the average was 608. True or false, and explain: the data show that on average, the schools in Iowa are doing a better job at teaching math than the schools in Connecticut.

a) For a representative sample of cars, would the correlation between the age of the car and its gasoline economy (miles per gallon) be positive or negative? b) The correlation between gasoline economy and income of owner turns out to be positive. How do you account for this positive association?

You miss 3 out of 10 questions on a science quiz and 4 out of 15 questions on a math quiz. Which quiz has a higher percent of correct answers?

A teaching assistant given a quiz to his section. There are 10 questions on the quiz and no part credit is given. After grading the papers, the TA writes down for each student the number of questions the student got right and the number wrong. The average number of right answers is 6.4 with an SD of 2.0. The average number of wrong answers is ______ with an SD of ______. Fill in the blanks----- or do you need data? Explain briefly.

Create a data file with 1000 lines. Each line in the file consists of a faculty first name, last name, rank, and salary. Faculty’s first name and last name for the ith line are FirstNamei and LastNamei. The rank is randomly generated as assistant, associate, and full. The salary is randomly generated as a number with two digits after the decimal point. The salary for assistant professor should be in the range from 50,000 to 80,000, for associate professor from 60,000 to 110,000, and for full professor from 75,000 to 130,000. Save the file in Salary.txt. Here are some sample data:.

FirstName1 LastName1 assistant 60055.95
FirstName2 LastName2 associate 81112.45
. . .
FirstName1000 LastName1000 full 92255.21

How do you open a Web page from a Python program?

How do you display a file dialog for saving a file?

A graph consists of vertices and edges that connect vertices. Write a program that reads a graph from a file and displays it on a panel. The first line in the file contains a number that indicates the number of vertices (n). The vertices are labeled as 0, 1, ..., n-1. Each subsequent line, with the format u x y v1, v2, ..., describes that the vertex u is located at position (x, y) with the edges (u, v1), (u, v2), and so on. Your program prompts the user to enter the name of the file, reads data from the file, and displays the graph on a panel.

Rewrite the above exercise to read data from a Web URL such as http://cs.armstrong.edu/liang/data/graph.txt. The program should prompt the user to enter the URL for the file.

How do you display a file dialog for opening a file?

How do you write and read numeric data?

Star A and Star B have different apparent brightnesses but identical luminosities. If Star A is 20 light-years away from Earth and Star B is 40 light-years away from Earth, which star appears brighter and by what factor?

To measure the effect of exercise on the risk of heart disease, investigators compared the incidence of this disease for two large groups of London Transport Authority busmen---drivers and conductors. The conductors got a lot more exercise as they walked around all day collecting fares. The age distributions for the two groups were very similar, and all the subjects had been on the same job for 10 years or more. The incidence of heart disease was substantially lower among the conductors, and the investigators concluded that exercise prevents heart disease. Other investigators were skeptical. They went back and found that London Transport Authority had issued uniforms to drivers and conductors at the time of hire; a record had been kept of the sizes. a) Why does it matter that the age distributions of the two groups were similar? b) Why does it matter that all the subjects had been on the job for 10 years or more? c) Why did the first group investigators compare the conductors to drivers, not to London Transport Authority executive staff? d) Why might the second group of investigators have been skeptical? e) What would you do with the sizes of the uniforms?