Answer Happy

A random sample is taken from the population of Texas college students. You use the sample to find out if there is a correlation between years of education and annual expenditure on books in the population. You are given the following information: Years of education is the X variable (independent), its mean (7)=13, its St. Dev. (52) = 3.46 Expenditure on books is the Y variable (dependent), its mean (1) = $15.70, its St. Dev. (sy) = 5.28 Here are observations for two cases, Jeff and Jane: Jeff has 12 years of education: X = 12, and he spent $85 on books this year: Y = 85 Write the formula for, and then convert Jeffs years of education into a Z score: Write the formula for, and then convert Jeff s expenditure on books into a Z score: Jane has 8 years of education: X = 8, and she spent $34 on books this year: Y = 34 Write the formula for, and then convert Jane's years of education into a Z score: . Write the formula for, and then convert Jane's expenditure on books this year into a Y score:
Write the formula for calculating the cross products: Calculate the cross product for Jeff: . Calculate the cross product for Jane: Now, assume you are working with the same sample, use the following information to calculate the correlation coefficient (R) and the coefficient of determination (R). You are given the following: n=25 The sum of the cross products, or (ZxZx) = 21.58 . Write the formula for the correlation coefficient (R): . Calculate the correlation coefficient: • Interpret the correlation coefficient (strength and direction)
• Calculate the coefficient of determination (R) and then convert it to a percentage: . Write your interpretation of R? (what does it tell you about this relationship): Assume you are working at the 0.05 level of significance, what are df? What is the R critical value? . Write your finding in terms of the Null Hypothesis, will reject or fail to reject the null? So, is there a significant association between Years of Education and Expenditure on Books per year?