Question Details

STAT 500 week 6 quiz ch 10

Question 1
Given the linear correlation coefficient r and the sample size n, determine the critical values of r. Use your finding to state whether or not the given r represents a significant linear correlation. Use a significance level of 0.05. r = -0.844, n = 5 
Question 2 
A set of data consists of the number of years that applicants for foreign service jobs have studied German and the grades they received on a proficiency test. The following regression equation is obtained: y = 31.6 + 10.9x, where x represents the number of years of study and y represents the grade on the test. What does the slope of the regression line represent in terms of a grade on the test? 
Question 3 
Find the value of the linear correlation coefficient r. The paired data below consist of the test scores of 6 randomly selected students and the number of hours they studied for the test. Hours 5 10 4 6 10 9 Score 64 86 69 86 59 87 Question 4 
Select the appropriate conclusion based on the following result: There is no significant linear correlation between scores on a math test and scores on a verbal test. 
Question 5 
Use the given data to find the best predicted value of the response variable. Eight pairs of data yield r = 0.708 and the regression equation y = 55.8 + 2.79x. Also, mean y = 71.125. What is the best predicted value of y for x = 5.7? 
Question 6 
Which of the following is NOT one of the most common sources or errors made in interpreting correlation results? 
Question 7 
Which of the following describes the coefficient of determination? · Question 8 
Use the given information to find the coefficient of determination. A regression equation is obtained for a collection of paired data. It is found that the total variation is 29.045, and the UNexplained variation is 13.833. Find the coefficient of determination.(Hint: You must first find the explained variation.) 
Question 9
Which of the following is a property of the linear correlation coefficient r? · Question 10 
Use the computer display to answer the question. A collection of paired data consists of the number of years that students have studied Spanish and their scores on a Spanish language proficiency test. A computer program was used to obtain the least squares linear regression line and the computer output is shown below. Along with the paired sample data, the program was also given an x value of 2 (years of study) to be used for predicting test scores. The regression equation is score = 31.55 + 10.90(years). Pred Coeff Std Dev T P Constant 31.55 3.360 4.96 0.000 Years 10.90 1.744 6.25 0.000 S = 5.651 R Sq= 83.0% R Sq (Adj) = 82.7% Predicted Values Fit Std Dev Fit 95% CI 95% PI 53.35 3.168 (42.72, 63.98) (31.61, 75.09) For a person who studies for 2 years, obtain the 95% prediction interval and write a statement interpreting the interval. 
Question 11 
Which of the following research hypotheses would be answered using a multiple regression?