REFERENCES 25 



(a) Make a table showing values of -Xl, e~ Xl , and N e~ Xt for various 

 values of / (years), assuming that N = 100% at/ = 0. 



(b) From the results, make a plot of JV vs t, and estimate the half-life (the time, 

 r, in years, when N = 50% of A ). 



(c) Sketch decay curves for P 32 (t = 14.3 days), I' 31 (8 days), C' 4 (5100 years), 

 Co 60 (5.3 years), Po 210 (138 days), and Ra 226 (1620 years), all on the same 

 graph. Compare them. 



REFERENCES 



1. Petrie, P. A., et al., "Algebra — a Senior Course (for High Schools)," The Copp 



Clark Publishing Co. Ltd., Toronto, 1960. (See p. 314jffor discussion on incre- 

 ments.) 



2. Thompson, Silvanus P., "Calculus Made Easy (Being a Very Simplest Introduc- 



tion to Those Beautiful Methods of Reconing which are Generally called by 

 the Terrifying Names of the Differential and Integral Calculus)," 3rd ed., 

 MacMillan& Co. Ltd., London, 1948. 



3. Mainland, D., "Elementary Medical Statistics," W. B. Saunders Co., Philadel- 



phia, Pa., 1952. 



4. Moroney, M. J., "Facts from Figures," 3rd ed., Penguin Books Ltd., Toronto, 



1956. 



