Astronomy 23/223 In-Class Exercise:

How Old is our Solar System?

In this exercise, we will calculate the age of the igneous rocks that make up the oldest parts of the Moon, which are the anorthosites in the highland areas. The dates we will use came from a paper by Papanastassiou and Wasserburg (1972).

Determine the age of these inclusions by filling in the following worksheet.

Linear Regression the Old-Fashioned Way
(Fill in the Blanks...)

 X Data 87Rb/86Sr Xi Xi2 Y Data 87Sr/86Sr Yi Yi 2 Xi·Yi Sample 1 0.03298 0.70127 Sample 2 0.04614 0.70209 Sample 3 0.02414 0.70060 Sample 4 0.17130 0.70954 Sample 5 0.15250 0.70840 Sample 6 0.13800 0.70748 Sample 7 0.13650 0.70758 Sample 8 0.12680 0.70733 Sample 9 0.09050 0.70497 Sample 10 0.07280 0.70373 SUM

= ________ = _________

= average X = ________ = average Y = ________

= _________ = ________

= ________

Now, solve either form of the following two equations, and you'll know the equations of your line!

Equation for regression line is: Y = slope · X + intercept

 Home | Syllabus | Course Schedule | Images and Data | Homework | Homework Answers In-Class Exercises | In-Class Answers | Exam Review | Exam Answers | Student List | Contact Darby | Summer Internships | More on Astronomy| Bus Schedule This page was created by Darby Dyar and is maintained by Darby Dyar and Rebekah Robson-May. Last updated on 12 September, 2003 .