least-square regression line

[mollieduff]

Someone please help me!!!!! I am desperate!!!!!! Due tomorrow!!!!!!!!!

How do I find least-square regression line either on a calculator or by hand?

I also have these questions if anyone wants to help me with them. Bottom line calculator not functioning right and can not calculate anything to do with stat's. Homework due tomorrow and need some major help. Don't want someone to do it for me but just to either help me or send me to a website with a free TI-83/84 calculator.

Thanks for reading this and thanks for your help :grin:



The purpose of this project is to find the least‐squares regression model for the given set of
data, and then use the model to make predictions.

The following table shows the average poverty thresholds for one person for selected years
from 1990 to 2005, taken from U.S. Census Bureau. Align the explanatory variable (Year) with
x as the number of years after 1980. Place your x‐values in List 1 and the corresponding
response variable y‐values (Income dollars) in List 2. Use your TI 83/84 calculator to graph a
scatter plot of the data points. You will be graphing your least‐squares regression model on
the same window as your scatter plot so that you can visually determine how well the least squares
regression model fits the observed data.

Year 1990 1995 1998 1999 2000 2001 2002 2003 2004 2005
x
Income ($) 6652 7763 8316 8501 8794 9039 9182 9573 9827 10160

1. Use your graphing calculator linear regression feature to obtain the equation of best fit
for the data and copy the rounded equation in Y1. Produce a graph of the scatter plot
showing the linear model of best fit going through the data points. Note the fit. Record
the equation of this model. (Round to 3 decimal places.)
____________________________________________________________________

2. What is the correlation coefficient?____________________

3. Is the model a “good” fit? (Answer Yes or No)_______________________________

4. What is the coefficient of determination? ___________What percentage of the
variability in y is explained by the least‐squares regression line?_________________

5. State the predicted incomes for Years 2000 and 2005 according to your linear regression
model and compare these predicted incomes for Years 2000 and 2005 to the observed
(actual) income for the given years found in the above table. (Round incomes to the
nearest whole dollar.)

Year 2000 Predicted Income: ______________Year 2000 Actual Income:_____________
Residual for Year 2000____________________

Circle the correct choice:
Year 2000 Observed Income (a) is less than (b) is greater than (c) is the same as
the average income for Year 2000.

Year 2005 Predicted Income: ______________Year 2005 Actual Income:_____________
Residual for Year 2005____________________

Circle the correct choice:
Year 2005 Observed Income (a) is less than (b) is greater than (c) is the same as
the average income for Year 2005.

6. Using the least‐squares regression model that you found for this data set, predict the
average poverty threshold for one person for the year 2007. (Round to the nearest
whole dollar.) __________________________________________________________

7. Give a reason why this model may not be reliable for making a prediction for the year
2030.___________________________________________________________________
________________________________________________________________________
________________________________________________________________________
________________________________________________________________________