STA2023 Quiz 3

In the Fall 2011 STA 2023 Beginning of the Semester Survey, students were asked how many parties they attended every week and how many text messages they sent per day. The researcher decided to make the number of parties attended per week the explanatory variable and the number of text messages sent per day the response variable. Using the information in the output below, find the value of r, the correlation coefficient.

In 1996, the General Social Survey included a question that asked participants if they had ever volunteered for the environment. This information is provided below divided by political party. What is the conditional proportion of Republicans who volunteered for the environment?

A study found a strong positive correlation between ice cream consumption and the number of violent crimes committed each month.Some people may take this as an indication of how refined sugars make people violent. This is an example of:

Mark the following statement as True or False. "The value of correlation, r, is affected by outliers."

A simple linear regression analysis was conducted to predict the Exam 3 score of students in STA 2023 based on their Exam 1 score. The analysis yielded the following results: y-hat = 50.57+0.4845x. The range of exam scores for both tests was about 30 points to 102 points. Which of the following is the best description of the y-intercept of the line(if appropriate)?

From 1975 to 1986, the General Social Survey asked its participants if they favored or opposed capital punishment. A least squares regression line was calculated to predict the percent that favored the death penalty based on the year. The least squares regression equation is yhat= -1859+0.9753x. Interpret the slope for this equation.

Below is a scatterplot for the number of fish caught per a six hour fishing episode by day for a Ratteltrap lure. Which of the following statements, describes the scatterplot?

Below is a scatterplot for the number of fish caught per a six hour fishing episode by day for a Ratteltrap lure. What value of r best describes the scatterplot?

A least squares regression line was created to predict the Exam 3 score of STA 2023 students based on their Exam 1 score. The study found that the value of R-squared was 28.8% and the least squares regression line was yhat=50.57+0.4845x. What is the correlation coefficient, r?

In 1996, the General Social Survey included a question that asked participants if they had ever volunteered for the environment. This information is provided below divided by political party. What is the conditional proportion of Independents who volunteered for the environment?

The following appeared in the magazine Financial Times, March 23,1995: "When Elvis Presley died in 1977, there were 48 professional Elvis impersonators. Today there are an estimated 7328. If that growth is projected, by the year 2018 one person in four on the face of the globe will be an Elvis impersonator."This is an example of: