statistics

The table shown gives the national average pupil-teacher ratio in public schools over selected years. Year Ratio a. Find the equation for the least squares line. Let x correspond to the number of years 1992 19.4 since 1992 and let y correspond to the average number of pupils per 1 teacher. 1994 b. Use the answer from part (a) to predict the pupil-teacher ratio in 2020. Does this 1996 18.9 seem realistic? 1998 18.2 c. Calculate and interpret the correlation coefficient. 2000 16.8 a. The equation for the least squares line is Y= b. Using the answer from part (a), the pupil-teacher ratio in 2020 will be C. The correlation coefficient is_ which indicates a strong linear correlation. The total amount of consumer credit has been increasing steadily in recent years. The following table gives the total 2 outstanding consumer credit (in billions of dollars). Answer parts (a) through (e) below. Year Consumer Credit Year Consumer Credit 2004 2219.5 2009 2553.5 2005 2350.8 2010 2645. 2006 2465.0 2011 2756. 2007 2551.9 2012 2926.3 2008 2595.1 2013 3097.2 a. Find an equation for the least squares line, letting x equal the number of years since 2000? b. Based on the answer to part (a), at approximately what rate is consumer credit growing per year? c. Use the result from part (a) to predict the amount of consumer credit in the year 2017? d. If this trend continues linearly, in what year will the total debt first exceed $4000 billion? e. Find and interpret the correlation coefficient The correlation coefficient is_ which indicates a strong linear correlation 3 For the following table of data, a. Draw a scatterplot. b. Calculate the correlation coefficient. x 1 2 3 4 5 6 7 8 9 10 c. Calculate the least squares line and y 0.3 0.8 1.3 2.3 2.8 3.3 3.3 4.3 4.8 5.3 graph it on the scatterplot. d. Predict the y-value when x is 11